Newly updated and upgraded, here is the database that I use with SCIDvsPC: 
MILLBASE1019 <--click to download (135 megabytes)
The filename refers to the TWIC number.

• Free
  
• Current as of today, May 21, 2014-- i.e., TWIC volume 1019
  
• Contains over 1.6M games
  
• Contains historical games 
  
• Contains modern (1990+) games between players with ELO ratings over 2200
  
• Also contains modern games where only one player has an ELO rating over 2400
• Annotated games slow down database functions like searches, possibly raise copyright issues, and have been purposely omitted
• MillBase is in SCID format only; works with SCID and SCID forks
  
• Download is compressed in 7-zip format at only 60% of uncompressed size

My goal with this database is to strike a balance of size and quality for regular use by chess hobbyists of all levels.  At this point I also prefer and recommend SCIDvsPC over the original SCID.

Here is my attempt to compile an enjoyable, practical, and fun 1.e4 repertoire based solely on high-quality(!) free videos hosted at YouTube.  Most of the presenters are quite strong players/trainers!  This is not an airtight or exhaustive repertoire but all the videos hit the big ideas and, for the most part, avoid drowning in minute details.  I favored short and sweet videos, although the lengthy entry on the Scotch Game could not be omitted due to the charisma and practical strength of its presenters.

Here is how the YT repertoire breaks down:
Scotch Game presented by Kingscrusher (2200 FIDE) and Paul Gheorgiou (2300 FIDE)
Sicilian, Czerniak-Gelashvili variation (2.b3) (and Part 2) by IM Andrew Martin
French, Nunn-Korchnoi gambit by SuperChessGuru and siciliandragon28: Part 1, Part 2
Caro-Kann, Spassky gambit by GJ_Chess (or Two Knights by FM Charles Galofre: Part 1, Part 2)
Scandinavian, Nf3/d4/c4 systems (and Part 2) by GJ_Chess
Pirc, f3/g4 attack by Majnu2006
Alekhine, Balogh variation (4.Bc4) by IM Vojislav Milanovic

As the Sicilian coverage is the lightest, here is a PGN of games played by Gelashvili in his pet line.  I think it helps to think of the opening as a reversed Queen's Indian.

Note: A full 1d4 YT repertoire has already been done by IM Christof Sielecki.

Youtube chess legend, Kingscrusher, has started an inspiring new series on the career highlights of the top sacrificial artists in chess history.  The artistic side of chess is rarely displayed in such clear focus.

• Morphy
• Spielmann
• Alekhine
  
• Nezhmetdinov
• Bronstein
  
• Tal
• Fischer
• Kasparov
• Shirov
• Kramnik
  

Who is next?  Off the top of my head, these players are also famous for Sacrificial Artistry: Anderssen, Keres, Spassky, Stein, Velimirovic, Hodgson, Hector, Topalov, Sutovsky, Jobava.  Even within this league of sacrificial artists there are distinctions. Some approached chess with the subtlety of a chainsaw hacker, others played imaginative and fantastic conceptions (Nezh, Keres, Bronstein), still others conveyed a sense of epic/unrelenting power (Alekhine, Kasparov, Topalov).  Viktor Korchoi, one of the greatest defenders, was quoted as saying that the greatest attackers in chess history through the 1970s were: Alekhine, Keres, and Spassky.  I find this subject fascinating.  I have made a detailed study of the Art of Sacrifice at my hobbyist level.

Here is my list of the three best chess apps for Android (my opinion):

• Entering games with variations and engine analysis:  Droidfish
• PGN viewer:  Chess PGN Master
• Opening tree functions:  Chessbase

And here are two honorable mentions:

• Training functions:  Perfect Chess Trainer
• Online play:  Mobialia Chess
  

I do not have a favorite for tactics puzzles, but am open to suggestions.

UPDATE: My favorites for puzzles are: TacticTrainer and EndgameTrainer, both by CoreGames.

Everybody knows that the move f2-f3 drives a toothpick into Black's heart.  White's only real concern is what moves to place around it as accompaniment.  After carefully selecting an action verb in the present-progressive tense, a unique font, and high-contrast colors, I am proud to announce my forthcoming Opening Repertoire Book for White.  Rock and roll.

I wondered what a reading list based on the 16 world champions would look like.  The 25 books in the slideshow probably contain approximately 1,800 games.  I imagine that a person who actually studied all of them could not avoid reaching a playing strength of international standard.

Although chess is lucky to have a rich written legacy from its lineage of champions, it is a shame that there are deficiencies in the list.  For instance, there is no definitive book on Spassky, and Euwe's book on his own games has been out of print for 30+ years.

I've read only 1.5 of the books in the slideshow: Capablanca's Best Endings by Chernev and Alekhine's My Best Games 1924-1937-- though I've read portions of Lasker's Manual and Capablanca's Chess Fundamentals.  I've also read The Art of Attack by Vukovic, which is essentially a treatise on the middlegame methods of Capablanca and Alekhine.  (Vukovic wrote that no master up to the time of publication, 1965, contributed anything to his subject that was not already fully developed by Capablanca and Alekhine!)

I can also give honorable mention to other worthy books along the same lines:

• Beim, Paul Morphy: A Modern Perspective
• Spielmann, The Art of Sacrifice
• Keres, Road to the Top & Quest for Perfection
  
• Bronstein, Sorcerer's Apprentice
• Larsen, Master of Counter-Attack
  
• Korchnoi, My Best Games
  
• Marin, Learn from the Legends
• Kasparov, MGP series

“When you lose, you really feel a sense of self ... You actually feel that you are being taken apart, rather than just your pieces.”
--Viswanathan Anand

The rest of Vishy's interview is published at the Financial Times.  'Tis one of the best chess interviews I've read in a while.

Other champions speak of what it feels like to win, or as Vishy paraphrases Fischer in the article, "to crush a man's ego."  Vishy talks about what it feels like to lose.  But then, the last two decisive games between Anand and Carlsen were very painful, flesh-rendering ordeals.

I am looking forward to this match!  I want Magnus to win, but I don't think he should be a 3-1 favorite as the oddsmakers have it.  Anything can happen in a short match, and Anand, at number 8 in the Live Ratings, is already playing on borrowed time and has nothing to lose.

I have now completed a video series covering all 37 games in this book, totaling almost 9 hours.  I made the first 14 videos in December 2008, while still officially a Class "B" player.  The quality is up and down, but I would single out 19, 24, and 12 as a few of the better ones.  A few that are not so good are 4, 18, and 27.

As a training idea, I can recommend going over the raw game score without annotations and without an engine.  Try to figure out the game for yourself-- especially try to see where the loser could have (1) avoided problems in the first place and (2) defused Spielmann's initiative.  After you have reached your own conclusions, you can consult the video (or the book or an engine) to compare your conclusions.  For this purpose I am giving the PGN file below.  Here is also a link to purchase the book.

SHAM SACRIFICES
Positional Sacrifice: leads to forced recovery of the sacrificed material with an improvement in position.
    Game  1           8:44         Spielmann - Pirc, 1931
    Game  2         10:10         Spielmann - Schlecter, 1906
    Game  3         13:11         Pirc - Spielmann, 1931
Sacrifice for Gain: leads to an advantage in material, the sacrificed material being regained by force and with interest.
    Game  4         12:31         Bogolyubov - Spielmann, 1927
    Game  5         10:58         Spielmann - Muller, 1933
Mating Sacrifice: leads to checkmate or to a decisive gain of material.
    Game  6         21:16         Spielmann - Honlinger, 1929
    Game  7         12:19         Spielmann - Tartakower, 1925
    Game  8         11:22         Spielmann - Grunfeld, 1929
    Game  9         12:17         Spielmann - L'hermet, 1927

REAL SACRIFICES
Sacrifice for Development: aims at an unnatural acceleration of one's development.
    Game 10         16:26         Schories - Spielmann, 1905
    Game 11         11:46         Bernstein - Spielmann, 1906
Obstructive Sacrifice: slows down the opponent's development.
    Game 12           9:23         Spielmann - Landau, 1933
    Game 13         16:16         Spielmann - Honlinger, 1933
    Game 14         16:08         Spielmann - Bogolyubov, 1932
    Game 15         13:05         Spielmann - Walter, 1928
Preventive (Anti-Castling) Sacrifice: intended to prevent the opponent from castling.
    Game 16         16:28         Spielmann - Duras, 1905
    Game 17         13:42         Spielmann - Mieses, 1910
    Game 18         18:05         Mieses - Spielmann, 1910
    Game 19         25:10         Gereben - Spielmann, 1934
Line-Clearance Sacrifice: aims at the early employment of rooks on open lines.
    Game 20         10:06         Spielmann - Flamberg, 1914
    Game 21         16:55         Spielmann - Eljaschoff, 1903
    Game 22         12:56         Spielmann - Grunfeld, 1922
Vacating Sacrifice: procures access for a particular unit to a more favorable square.
    Game 23         19:30         Spielmann - Janowski, 1907
    Game 24         17:19         Spielmann - Reti, 1912
Deflecting or Decoy Sacrifice: lures or diverts enemy forces from the main field of battle.
    Game 25         15:18         Spielmann - Forgacs, 1910
(Castled) King's Field Sacrifice: breaks up the hostile King's castled position.
    Game 26         18:16         Spielmann - Dekker, 1934
    Game 27         10:38         Leonhardt - Spielmann, 1906
    Game 28         11:45         Spielmann - Duras, 1907
    Game 29         13:16         Spielmann - Bogolyubov, 1932
    Game 30         16:52         Becker - Spielmann, 1926
King-Hunt Sacrifice: drives the enemy King into the open, where it is exposed to danger.
    Game 31         24:27         A. Rubinstein - Spielmann, 1912
    Game 32         15:56         Spielmann - S. Rubinstein, 1933

SACRIFICIAL VALUES
The Exchange Sacrifice
    Game 33         15:24         Treybal - Spielmann, 1922
    Game 34         12:24         Spielmann - Tarrasch, 1923
    Game 35         10:25         Spielmann - Tartakower, 1909
The Queen Sacrifice
    Game 36         15:08         Spielmann - Maroczy, 1907
    Game 37         10:32         Spielmann - Moeller, 1920

Four-hour commentary by Peter Svidler and Yasser Seirawan -- I'm surprised this has only 3,000 views.  What a privilege to sit in on a commentary between two former World Top 15 players.  It helps that Svidler has the diction of an Oxford professor.  Full of extemporaneous insight and intuitive assessments.

Black is a talented 10-year-old kid rated about 1600 USCF.  White is a lifetime 1800 with about 3,000 rated games under his belt.  The kid has thoroughly outplayed the wily old veteran, but played the hideous ...f7-f6 from the diagram position at left.  Like most endgame mistakes, this is a completely unnecessary pawn move.  It opens the 7th rank and untethers the knight which can now be harassed.  Correct was simply to activate the pieces-- i.e., Kf8-e7-f6 and then have a look around.  Instead, this really, really, actually happened in a rated club game: