I think Fallout 3 and Left 4 Dead tied as having the longest lines of the show. Left 4 Dead is by Valve Software. It's a 4 player co-operative game in which you play 4 people surviving an onslaught of zombies. These are boring stupid zombies either. These are fast lethal fuckers out for blood.
There was constantly a horde of people lined up in a queue on booth sides of the kiosk. One headed to the 4 PCs set up. The other headed to the 4 Xboxes set up. Lines for PC versus Xbox were about equal.
This is really where the hardcore video game enthusiasts came to play. Everyone was yelling at each other what they were doing, working together to fight off the zombies. Left 4 Dead had the most interaction out of any game on the floor and everyone I saw walk away from the demo had a smile on their face. Players laughed. Players cheered. Players shouted their victories.
Left 4 Dead definitely feels like the feel good game of this holiday season.