Rockstar is sort of an oddball for me, but overall I like their games. I absolutely hated GTA4, I honestly don't know why it got all of those perfect scores. Why did I hate it you may ask? Well, let me tell you!
Nico as a character was completely schizophrenic. For example I take one mission where he has to watch over a gang deal as a sniper to which he eagerly agrees to do so going "Yeah...yeah, alright, that sounds good." Then, after a brief 5 minute rampage for whatever reason, I go to another mission where that one gay guy wants to go boating to which Nico responds by yelling at him and saying "I am hiding from the mafia you idiot! I can't expose myself like this!" What? You had just eagerly accepted a hitjob, and went on a rampage, why do you all of a sudden care? This is a problem with open world games; consistency, and Rockstar, I think, does it the worst.
Also, the weapons were bland and uninteresting. There are literally only a few kinds of variety. A rocket launcher, shotgun, pistol, rifle, and sniper. That's really about it. And the only other weapons are clear upgrades of those weapons. There's no dildo. No katana. No tank. Not even any fun cheats. It had gotten so "dark" and "edgy" and "serious" that it really drained all the fun out of it. And I think it would have been fine if it hadn't been schizophrenically driving that line between "goofy fun" and "gritty realism". It still had all the wacky stereotypes but it tried to play them straight.
I dunno, I guess it just didn't click with me. Red Dead Redemption was much better, though it still fell into inconsistent territory and at times it felt padded out. Still, I enjoyed it much more than the piece of tripe GTA4 was.