most of the games i think were overrated aren't terrible games, i would say either average or above average. this isn't in any order, but off the top of my head:
GEARS OF WAR. in general this was a mediocre game in every way except graphics. the story isn't interesting at all, it ends up going no where, the AI is really bad, and a lot of the parts in the game just aren't fun (have no idea what the fuck they called those bats, but any level that had them in sucked). people really bought into the graphics for this and i think is why it got such high ratings.
the HALO series. i could go on forever about the problems with the three in the series, but i'll simply say halo only did well because the console it was on did terrible.
XENOGEARS. this is at most an average RPG. the battle system was terrible, the game was much longer than it should have been, the pacing was bad, the story was ridiculous, and even the storytelling itself was poorly done. the one credit i give to this game is that is does a decent job with the locations and being a pretty big scale, it was an ambitious game but it executed a lot of it badly.
METAL GEAR SOLID 2. i have no idea why this game is so highly acclaimed. the game had the fundamental metal gear set-up, but did mostly everything wrong. i don't have a problem that they let the story / cinemas hijack the gameplay, but they did terrible in this regard. it would have been a great game if they could have succeeded in telling some kind of meaningful story with better characters, but this wasn't the case. technically this game is very sound, and has good core gameplay, but it is very hard to get into when the main drive of the game is such a trainwreck (for those of you who played MGS2 and may have forgot, THE PRESIDENT GRABS YOUR DICK).
man, i could spend all day listing stuff. i'm going to cut off here and just say generally everything is wildly overrated.
also, ICO and SoTC aren't fun games. they heavily rely on the story and atmosphere to drive the game, and if you're not into it, you won't like the game. that said ICO didn't appeal to me at all, but i liked SoTC a lot more because i thought it was very unique in going for a boss only game. i wasn't really impressed with what they did in terms of storytelling or atmosphere, but i admit they did a better than typical job with it.
maybe games get good ratings because they are given by professionals doing their jobs, and not random people that whine about it on the forums? idk
there is nothing professional about the vast majority of video game reviewers. the average rating for any given game last time i checked on gamerankings.com was something to the effect of 72% across all sites. i have played maybe a handful of games this year, but according to what the average of these sites say i should virtually be checking out every game. most reviewers are just guys who somehow land a job rating games, and there are huge conflicts of interest because you don't want to piss companies off with low ratings when they give you exclusive previews and send you free shit.
you are much better off reading what people said about the game who actually had to dish out money for it and don't have to speedplay the game to get a review done in time.