After Brad Gallaway put together his backlog, I though it might be fun to do mine. Here they are, ranked by system then by preference. Bear in mind that theoretically I'm working on a book on 1990s video games, and would like to be able to make more time for that, so in order to not have "Every 90s game I never played" as a list, I'll only list the ones I specifically acquired and haven't played before (a general rule for the list anyway.
Syphon Filter - Yeah, I never played this, picked it for the book for $2.
Persona 4 - I started this, got 30-40% done, but got overwhelmed and let it go.
We <3 Katamari
Disgaea - I've started this and stopped at the same place 2-3 times, early on. Would like to push further someday.
Buffy The Vampire Slayer: Chaos Bleeds
Metroid Prime 2 - I've had this for years, but every time I start, I want to play Metroid Prime 1 then I do and get my Metroid fix. One day.
Zelda: Ocarina Of Time
Radiant Historia - started this, maybe 25% through. I enjoy it but it hasn't grabbed me and demanded I keep playing.
Castlevania: Portrait Of Ruin - started this, enjoy the central out-of-the-castle conceit, but never pushed myself to go back. You know, if I had a job where I left the house, I'd play more DS games.
Phoenix Wright: Ace Attorney - Dubious, but it has so many fans I want to do it.
Dragon Quest IV/VI - picked these up for cheap, played a notable amount of IV, haven't started VI.
Lost Magic - Had this one on my list for so long I kind of forgot why.
Monster Hunter Tri
No More Heroes 2
Little King's Story - Started this, very much liked it, but was driven away by Nutcracker music (sister's recital aversion therapy)
Metroid Prime 3
Zelda: Twilight Princess - I did play most of this on the Gamecube when it was released, but it probably deserves a Wii play.
Super Smash Bros Brawl - Obviously it's best multi-player, but it's terrible with the Wiimote. So I need to get a Classic controller or two and have some friends over.
NHL 2K10 - I read this was one of the best games for use of the motion controls, but the controls didn't really click with me, and I think I have a bum shoulder.
God Of War III - Slowly working my way through this one, and it's top of the list of New PS3 game since it's borrowed.
Brutal Legend - I mean, Double Fine.
3D Dot Game Heroes
Heavy Rain - I have this (borrowed), I started it, and I can't read it on my non-HD TV.
Brothers In Arms/Motorstorm - These were hand-me-downs, but I'll probably give them at least a quick try before trading them.
The Old Republic - Like anything's getting played as long as this is #1....
Fallout: New Vegas
Bulletstorm/Portal 2 - I want to feel like my 2011 Best Games list is more complete. Own these. Haven't played. Should.
Bastion - Okay, I've played this, but is it New Game+ time? It should be, right?
Atom Zombie Smasher - This is kind of getting played alongside The Old Republic, so it's not quite a "backlog".
Skyrim - Yeah, I'll go back. Maybe let some mods and DLC show up?
Dragon Age: Awakening
Just Cause 2
Recettear - Played long enough to get a good feel for the mechanics but not so good I didn't fail. Would like to go back and win.
King's Bounty/Crossworlds - I would like to finish one or both of these
SpaceChem - Played a while, need to play more.
Binding Of Isaac
Shogun 2: Total War - NEVER ENOUGH
Rock Of Ages
Beyond Good & Evil
Mirror's Edge - Probably would be higher, but I have it on disc and don't have a CD-ROM drive at the moment.
Baldur's Gate II - I played this long enough to get a good idea that there was something impressive, but got stuck and said I'd come back to it.
E.Y.E. Divine Cybermancy
Frozen Synapse - Was not impressed when I started playing, but the Steam gift contest will push me into at least another try.
World Of Goo
Battle For Wesnoth
Vampire The Masquerade Bloodlines
Tomb Raider/Myst - These two are probably close on the "Most Important Game I've Never Played" pedestal
Prince Of Persia 2008
Mount & Blade Warband
Time Gentlemen, Please!/Ben There, Dan That
Might & Magic Heroes VI - I liked this a lot and I want to get back and finish more of the campaigns but oh man.
Terraria - Gave this a quick start, but was immediately pissed off by the lack of tutorial or manual. I guess it's hip to make your fans put videos up on YouTube instead of teaching your players how to play. Doubt I'll go back, honestly. Or play MineCraft. But I probably should.
Thief: The Dark Project/Thief: Deadly Shadows
Orcs Must Die
Oddworld: Abe's Exoddus/Oddysee
Monday Night Combat - I played this a bit and really liked it but there are so many team-based shooters around I'm not sure I'll ever go back.
Medieval Total War II/Kingdoms - I have so much love for the Total War but they're such an investment.
Max Payne I/II
Inside A Star-Filled Sky
Grand Theft Auto V
Dead Space 2
Cthulu Saves The World/Breath Of Death VII
Avadon: The Black Fortress