I just got this the other day and I'm enjoying the hell out of it. Just driving around watching the random stuff go down is a full game in itself. This just happened to me today:
I was tooling around on a bike when this taxi nearly plows into me. He's weaving all over the road, hitting cars, meanwhile a cop car is in hot pursuit. I ditch the bike and take a car because I wanted to follow the chase and see what happened. The cop car is right behind the taxi, and the taxi tries to take a corner too sharply. He clips the curb and is bounced across the road into a building. The cop car then plows into the taxi, and both drivers hop out and start shooting at eachother. Meanwhile, all the other cars that were hit along the way fly into the scene, smashing into everyone, trying to get sweet AI revenge.
I get out and sit back to watch, but a group of Ballas spot me and start shooting. They accidentally hit the cop though, and so he switches targets and starts going after Ballas. He kills all but one, the Balla then steals the car I pulled up in and takes off, with the cop in hot pursuit. By this point the scene on the street is this huge pile of cars and at least 20 peds melee'ing it with bats and knives and guns.
The funniest part though was the whole time, there were about 5 kids sitting on their bikes watching the whole scene go down, ringing their bells like some hood version of Children of The Corn.