If you obsess about the right things (football, barbecue and/or beer) tailgates are wonderful. I've been tailgating at Texas games for a long time and I love it! It's the only social situation I know where AS is not a problem. My group is usually about 15-20 people, but more show up for big games. We had almost 40 for UT-Ohio State last year and may also for UT-Nebraska this year. A lot of people just go to party and don't even bother attending the game. It's like a holiday six times a year.
A lot of people in my group homebrew so we sample and comment on each other's beers and compare brewing notes. We also have margaritas, bloody maries (made with Tito's Texas vodka), soft drinks and bottled water for the non-beer drinkers among us. We also talk football with other people that care about it as much as I do. Being in Texas, we all like barbecue so somebody smokes a brisket and of course we sample and discuss at ridiculously great lengths.
For activities, we watch whatever other games we can pick up with rabbit ears a 13' tv running on a car battery / power inverter, pitch washers (a game similar to horseshoes), and of course play touch football. One time someone brought a Playstation 2 and we had an NCAA football tournament.
My tailgate is pretty ghetto compared to others around here. It's amazing how obsessive NT people can get when it comes to tailgating. I see a lots of huge flatscreen TVs and satellite systems running off generators. Enormous barbecue pits with wheels that are towed in behind vehicles. $100,000+ RVs Full-on living room sets with leather couches and a 70" plasma tv- in the middle of a field! But the most over-the-top thing I've seen is a group near us bought an old school bus, refurbished it, painted it burnt orange and white, outfitted the interior with hardwood floors, a pool table, nicer furniture than I have in my house, a generator, and full bar with three keg taps. And they built a deck over the roof with a retractable roof, nightclub-type sound system and light show with disco ball and numerous flat-screen tvs hanging from the roof. They spent thousands of dollars and who knows how many hours building this thing. I'll take some pics of it at the next home game.