Why do we play Tabletop RPG’s?

By "we" I mean gamers in general, not just those of my age demographic. Obviously, there isn't any one answer, so I will just break my reasons down for you.

1. To spend time with Friends – This is the penultimate answer for me. There is no other reason to play a tabletop game, IMHO, than to have a good time with others. Even if you play in a pick-up game at a convention, or your FLGS, the goal is to have fun. As we like to say on the USS Justice, "If you're not having fun, you're doing it wrong." There have been many time when an entire 4-5 hour gaming session consisted of nothing but telling stories/jokes, ribbing people or their characters (yes, S.M.U.R.F.E.T.T.E, I'm looking at you), or just generally laughing ourselves silly. (Just check out some of the Greyhawk Campaign Logs over a Greyhawk Grognard to see what I'm talking about.) So what if we got nothing done in game, everyone was able to have fun and that's a successful night in my mind.
2. To try out something new – For example, I was involved in the playtesting for Adventures Dark and Deep up until recently (scheduling issues) and it was a great time. We purposefully tried out wacky things just to see what the rules could do, and that was fun in and of itself. And it's always amusing when your Half Orc Fighter (with 18/63 Strength) rolls a 1 for damage in unarmed combat and nearly rips a guy's arm off. Mongo, you will be missed.
3. It's CHEAP! – Yeah, I know it seems trite, but once you buy the rules, you can play for an unlimited amount of time and you're using the most advanced processor on the planet to run the game (that's your brain, people). I don't know how many hours I played RPG's with my friends growing up, and usually only one person had to lay out the cash for the game for all of us to play. Much better than $40-60 per game that only lasts 20-40 hours of game time, not to mention the system to play them on. Pen and paper games are a bargain at twice price.
4. You just can't do it anywhere else – I run a monthly (usually) game of King Arthur Pendragon for my wife and a few friends, which we always have a good time at. We're using The Great Pendragon Campaign, which takes the players from 10 years before Arthur is born until after his death, which spans 80+ years. How many games, other than a tabletop RPG, will have that scope? Not only do the characters get married, have families and die, but they are succeeded by their offspring to carry on in the game. It's not just that it doesn't happen anywhere else, it CAN'T! Try to get a PS3 or Xbox game with that many facets to it and it would be cost prohibitive. You get close with MMORPG's, but even then the world events and expansions cost a pretty penny. This is an expensive book to buy (luckily, one of my friends, who is a player in the game, owned it already), but you can't beat the experience.

That's my list. Anyone out there on the interwebs have any other reasons?