360 version
My initial impressions are VERY VERY good. The animations are alright, but it's the way they blend into the physics that makes them interesting. The way people react when you bump into them on foot, or slam into them with your car looks awesome. The cars feel a bit more realistic than Vice City, which was the last one I played, but it's still very arcade. Shooting out of your car is nice. Flying through the windshield of your car is also nice
The cut scenes seem pretty well done. The cellphone is a real slick way to tie everything together.
The city is pretty big and me and my bro had a lot of really amazing car chases. Still haven't seen a wanted rating above 3, and 3 was pretty hard to survive. Gun combat and melee seem more difficult than previous versions and you die faster. You don't seem to take a lot of damage in crashes, but melee and bullets kill you pretty quick. The cover mechanics and aiming are very very basic Uncharted/Gears style, but it works pretty well. Melee is more interesting than it used to be with block and a couple different attacks you can use to string combos.
As for graphics, seems very good. The city is big, has lots of pedestrians and cars. It seems more "alive" than the other games. I don't notice the aliasing too much, but i'm playing on a 24" screen, so it obviously won't be as apparent in motion as it would be on a TV. Framerate is obviously not the highest, but very playable to me - better than previous GTA games on the consoles. Texture pop-in is noticeable in the distance, but not a big deal to me. Haven't noticed any screen tearing.
It's GTA. If you really didn't like the previous ones, you probably won't like this one. If you were on the fence or thought the previous ones were ok, I'd say definitely try this one because it's much more well rounded and polished, especially the "on foot" part of the game.
If the game continues to ramp up for me, I'd definitely rate it very high. Probably not a 10, but very high. I don't have too many games that I would rate a 10, but this definitely is on track to be one of the best games I've played in a while.
Will try multi-player tomorrow.