The 2008 Game of the Year is Super Smash Bros Brawl.
The runner up is Fallout 3.
The master thread for all of these contests can be found here.

Ok, it is time for a runoff vote.  Four games from the initial poll made the cut.  Additionally, 5 "Other" games got more than one write-in vote.  First, here are the four games that made the cut:

Persona 4 (PS2)
Even after the next generation systems had been on the market for several years, there was still a group of people raving about how you just had to play this Persona 4 game on PS2.  Gradually the game started to get ported to other systems as well, often as Persona 4 Golden.  The buzz about this game also prepared the way for people to receive the even more successful Persona 5.  Persona 4 scored a 90 on Metacritic at a time when most critics were really sick of PS2 games, and it sold over 4.5 million copies across all platforms (including the Golden version).

Fallout 3 (PS3/XBox 360/ PC)
Bethesda managed to obtain the rights to this series that formerly had a cult following.  With Fallout 3 that simply changed to having a huge and enthusiastic following.  Fallout 3 scores ranged from 90 to 93 on Metacritic and the game has sold over 12.4 million copies.

Metal Gear Solid IV (PS3)
Sony fans were happy to get this big name exclusive on the PS3 after previously getting only smaller titles or games that were also on the XBox 360.  MGS 4 scored a 94 on Metacritic and sold over 6 million copies.

Super Smash Bros Brawl (Wii)
Depending on what region you were in, you might have seen Brawl release either a few weeks before or a few weeks after Mario Kart Wii.  This combo excited customers to the point that the Wii would keep being in short supply.  Brawl scored a 93 on Metacritic and sold over 13.3 million copies.

Here are the five games that got enough write-in votes to join the poll:

Braid (XBox 360)
XBox Live Arcade started getting a lot of attention like it never had before in 2008, and the XBLA title that seemed to get the most attention was Braid.  This puzzle platformer from designer Jonathon Blow scored a 93 on Metacritic.

Tales of Vesperia (XBox 360)
The XBox 360 managed to get timed exclusivity on this 10^th entry in the Tales series, and consequently it was the 2^nd best selling XBox 360 game in Japan (behind only Star Ocean: The Last Hope).  Tales of Vesperia eventually sold over 1.5 million copies including all platforms and editions.

Dead Space (PS3/XBox 360/PC)
Surivival horror goes to outer space.  Metacritic scores for Dead Space ranged from 86 to 89 and it has sold over 1 million copies worldwide.

Mirror’s Edge (PS3/XBox 360)
This unique, first-person parkour game has sold over 2.5 million units worldwide.

Valkyria Chronicles (PS3)
Even after being out of the console market for several years, Sega showed they still know how to pull out innovative games from seemingly nowhere.   Join Alicia, Welkin and a whole cast of characters as a reimagined, fantastical retelling of WWII comes to life in a watercolor-like art style.  Sales of Valkyria Chronicles were initially weak.  However, over time the game gained a cult following, and with releases on several other platforms it has sold over 2 million copies total.

Runoff voting for 2008 Game of the Year will end on Thursday, Nov 16 at 11:59 PM, EST.

Games that didn't make the cut to the runoff:

Fable II (XBox 360)
Gears of War 2 (XBox 360)
Grand Theft Auto IV (PS3/XBox 360/PC)
LittleBigPlanet (PS3)
Mario Kart Wii (Wii)

Here are some other notable games for 2008:

Blazblue: Calamity Trigger (Arcade)
Street Fighter 4 (Arcade)
Tatsunoko vs Capcom: Ultimate All-Stars (Arcade/Wii)
Spelunky (PC)
God of War: Chains of Olympus (PSP)
LocoRoco 2 (PSP)
Monster Hunter Freedom Unite (PSP)
Advance Wars: Days of Ruin (DS)
Castlevania: Order of Ecclesia (DS)
Kirby Super Star Ultra (DS)
Professor Layton and the Unwound Future (DS)
Rhythm Heaven (DS)
Braid (XBox 360)
Castle Crashers (XBox 360)
Geometry Wars: Retro Evolved (XBox 360)
Left for Dead (XBox 360/PC)
Burnout Paradise (XBox 360/PS3/PC)
Call of Duty: World at War (XBox 360/PS3/PC/Wii)
Civilization Revolution (XBox 360/PS3/DS)
Dead Space (XBox 360/PS3/PC)
Far Cry 2 (XBox 360/PS3/PC/Mobile)
Guitar Hero World Tour (XBox 360/PS3/Wii/PS2)
Prince of Persia (XBox 360/PS3/PC)
Rock Band 2 (XBox 360/PS3/Wii/PS2)
SoulCalibur IV (XBox 360/PS3)
Tom Clancy’s Rainbow Six: Vegas 2 (XBox 360/PS3/PC)
Disgaea 3 (PS3)
Motorstorm Pacific Rift (PS3)
Pixeljunk Eden (PS3)
Resistance 2 (PS3)
Valkyria Chronicles (PS3)
Wipeout HD (PS3)
Animal Crossing City Folk (Wii)
Boom Blox (Wii)
Wario Land: Shake It! (Wii)
World of Goo (Wii/PC/Mac)

Fallout 3. Such an amazing experience for me. Shoutout to Dead Space, Rhythm Heaven, FarCry 2 and Castlevania OOE. Great year.

The easiest choice in a while. Valkyria Chronicles is by far the best game of 2008, the only game that comes even remotely close is Persona 4. After that it's Super Smash Bros. Brawl, MGSIV, LittleBigPlanet, and Soul Calibur IV a level or two below. 

Fable 2, Gears of War 2, Dead Space, and Fallout 3 were all fantastic games, but when I think of 2008, I think of the WoW expansion, Wrath of the Lich King! That expansion was peak World of Warcraft and I put hundreds of hours into that expansion. As a longtime Warcraft fan in general, it was so cool seeing Arthas again since Warcraft 3 (also top 5 best games of all time) and his return did not disappoint. It was an epic gaming moment when you finally fought him in the Icecrown Citadel raid! Amazing storytelling, even for an MMO.

Not to mention, one of the best cinematics ever in gaming!

My vote is for Dead Space. For me it beats out RE4.

1. Dead Space
2. Ninja Gaiden II
3. Knights in the Nightmare
4. Rock Band 2
5. Grand Theft Auto IV
6. LocoRoco 2
7. Left 4 Dead
8. Devil May Cry 4
9. The Void
10. Dissidia

I’m impressed by how many games I’ve actually managed to play here but there are still some I’d like to get around to. Persona 4, Fable II, Far Cry 2, Nuts and Bolts.

Dead Space.
From its brilliant crunchy combat to its chilling atmosphere, it's a horror masterpiece.
The way it imbeds you in its world, like how the HUD elements are all in-world is terrific, and it was one of the best looking and sounding games out there in 2008.

I went for littlebigplanet. Though the sequel was a little better than the first, it was my first experience with user created content. The game was one of the most charming games I’ve ever played. I wish the series could find footing again. Sack boy was a great mascot and all of the different customizations were really cool too

It’s not easy following 2007. I don’t envy this year.

My pick goes to Brawl. Amazing variety and content, and addictive brawling gameplay. And still the best single-player mode in the series.

I also loved Gears 2, Fable II, and Far Cry 2. Lots of sequels

Mirror's Edge! Super underrated game (and series). One of my favourite art styles of all time and first person platforming gameplay that has a surprisingly high skill ceiling; it makes it so so satisfying to pull off fast level runs successfully. I wish it was more popular - I really want another entry in the series :(

This was another excellent year for games imo. After Mirror's Edge is also love WipEout HD, Prince of Persia, GRID, Fallout 3, N+, Left 4 Dead, Pacific Rift, and World of Goo.