Personally I played Red Dragon in for the first time and loved it, as well as Samurai Spirit. I have more, but dont feel like listing all 7. 
Spirit Island!
I went to the Asmadi booth to pick up Impulse and came away with another Carl Chudyk game called Red, as well. Looks interesting. Also got Battle at Kemble's Cascade, Coup: Reformation, Pandemic: Contagion, Downwood Tales, and King of New York.
Nick discovered The Bravest Warriors Cooperative Dice Game and loved it. We'll be getting that. He also lost me my copy of Among the Stars by being certain it wouldn't sell out (spoilers: it did). Argent: The Consortium is on my future list, too.
Interestingly, that was the only (non->G) game I played during the con. One of our houseguests picked up a copy the first day and we played it Friday evening.
I actually didn't buy any games this year, although I saw a lot that looked interesting that friends bought (so I didn't have to 
). My own loot was mostly my annual Alea Tools purchase, a new dice bag (for the Sentinel Tactics dice), and some entertaining "Damn!" dice (for the Sentinel Tactics).
Here are some new things (for me; mostly not for everyone else) that I checked out during GenCon.
Wok Star and Damage Report are both real-time coop games that were pretty good; Damage Report felt like it had more replayability of the two.
Betrayal at the House on the Hill is an old reprint that I'd been meaning to check out for a while, but forgotten about. I picked it up (thanks for the heads up, Evan) and played a couple of games and everyone agreed that it was really fun.
In the realm of Carl Chudyk games, I learned Innovation and Impulse. Innovation was decent, but couldn't hold up to Glory to Rome. I didn't really get into Impulse. The idea was fine, but I wasn't crazy about the direct attack aspect of it and the cards I had during the demo game didn't work well with each other so I felt like I just had a lot of bad options the entire game. Let me know how Red is - I didn't see it.
Legends of Andor (I'm really just listing a lot of games that were released years ago, right?) was ok, but the demo was too quick to get a good sense of it. It has the shortest manual I've ever seen in a Fantasy Flight game. I would try it again.
I wanted to check out Downwood Tales, but never found myself by the Plaid Hat booth when I had enough time to really investigate it. I should probably deal with the Heart of Glorm first, anyway.
The guy that taught me Shadowrift was both extremely enthusiastic about the game and terrible at teaching it. It seems like it's worth trying again, but the demo guy didn't explain the rules well in advance, so the player that didn't understand how deckbuilding worked just couldn't figure out what was going on until we explained it to him. The rest of us had a hard time identifying the most threatening targets because he wouldn't tell us how the monsters behaved. So, bad demo but the game has potential.
Then Spirit Island won GenCon.
grysqrl, you really should come down more often. Our gaming tastes are pretty similar.
I'd definitely like to get down there again before too long. I'm carless, so it's a little tricky to be spontaneous. Also, I think I owe you and Nick a stroll around Chicago sometime.
Chicago terrifies me, but we will let you know if we're going to be up there.
I've checked out Damage Report several times, but each time the art just puts me off.
I played Tragedy Looper and enjoyed it; it's a time-travel-ish murder mystery, where you progressively learn more about the situation. It was fun, perhaps I'll buy it. (They were sold out that day.) The puzzles were perhaps a little too much combinatory logic.
I actually picked up Legends of Andor recently from someone who was leaving town. It looks like fun, although I haven't got it to the table yet. Saying it has a short manual is a little misleading, as many of the rules are on cards and are introduced to you slowly.
A friend picked up Assyria (which Mayfair Games seemed to be trying to dump), and I enjoyed the play we had of it. Lots of different strategies to try to exploit.
Next year I'll really try to have more than one day there!
Picked up a lot of new games at GenCon: Epic Resort, Say Bye to the Villains, Bravest Warriors card game, Munchkin Adventure Time, Super Dungeon Explore & Caverns of Roxor expansion, Shinobi Wat-Aah!, Adventure Maximus, Ruckus: The Goblin Army Game, Tools of a Hero Kind expansion for Boss Monster, Heroes Wanted, and Pathfinder ACG: Skull & Shackles.
I also received RARRR!!! Monster-Building, City-Stomping Card Game in the mail that week. Had to remove a few old games but condensed some of my bags to fit the rest. I've also pre-ordered a game called Dungeon Dwellers, plus the expansion. One game I was really interested in but was sold out when I finally decided to buy it is Samurai Spirit, got the promo for demoing it at least.
So not to be a buzz kill, but I thought I should let people know. My copy of Red Dragon Inn with two expansions was in Evan's car when it was broken into so I no longer have it. 
That's sad. 
To replicate the experience, get really drunk with friends and hit each other until someone is broke or passes out.
I second imprimis5's idea.
To add on to DefeatedDust's list (since we worked together to get games), we also got the Resistance, Cross Hares, Forbidden Desert, Betrayal at House on the Hill, and Star Fluxx.
The bad thing about running 16+ hours of demos in 2 days at GenCon...
...I didn't get to play *anything* :(
I feel ya buddy. I taught a ton of GSF. That was about it for Con hours haha
My wife and I arrived on Friday evening, picked up our badges, and had dinner with a friend who now works for FFG.
Saturday morning, we woke up, drove in, and I ran games from 10am until 11pm (with a short break for lunch and dinner in there).
Sunday, I did it again, starting at 9am and ending around 2pm (my last demo ran short, which was a blessing), which left me just enough time to jog through the dealer hall once and drop off a few copies of CSW to some of my industry friends/acquaintances. I did manage to swing by the >G booth long enough to say hi to Adam and drop him a copy for the >G crew. I hope he decided to share!