It is definitely not a 10. Graphical/texture pop-up and tearing, no mid-mission checkpoints, framerate problems, police cars that spawn directly into you, retarded drunk physics that do nothing for the game, and a somewhat lame soundtrack keep it from that.
It's really fun though. I'm sitting just over 51% now and the story's sort of going nowhere for some reason. It was really moving along for a while but then they started adding in all these other characters that don't seem to have anything to do with the actual story.
Also, it's really dumb that hot dog stands seem to just phase into existence in random places instead of being something you can track. It makes healing way more annoying than it needs to be. I've lost a ton of money just dying to get myself back to full health rather than wasting time.
Also, Niko is cool but honestly, I don't feel any development from him. He just says some sarcastic one-liner and then goes off and kills stuff. I'm sure the kids these days love that stuff but the previews for the game made it look like he actually really regretted what he was doing and I was really hoping for some sort of psychoanalysis of a murdering mercenary good guy.
I really wish Rockstar would actually make a game where you play a police officer. Start at beat cop, work your way up GTA style taking care of your area, with a nice story about how the gets tempted by bribes, whatever. I think it's just because I watched American Gangster recently. I think it'd be cool to have a dramatic police story though, rather than always being on the side of the drug lords/mob.
It IS the best GTA though. I will say that.