I really do find yahtzee's videos to be well researched and thought out. Yes all criticisms are personal opinions but yahtzee does incredibly well with being as accurate as possible. I know all of my friends who own Dead Space love the game to death, but really I do take yahtzee's stance on the game as being "startling" and not nessicarily "scary". Though I did get Spore before Yahtzee put up his review on the game and truth be told, there's an achievement in the game to get your creature from cell to space stage in one sitting and it's not a really hard achievement to obtain. Even after loving the game as much as I did for about the week and a half that I owned it, yeah yahtzee's completely on the ball with that one too.
Another game that I partially agree with him on is SSBB, I pretty much refuse to play this game at parties because of the amount of "Those guys" that insist upon playing SSBB despite the fact that most of us that don't own a Wii don't want to play a game for 5hours straight if we're not going to enjoy it. Though the part that I don't agree with is when he insists that it's about as easy as smashing your face against the controler and winning games. I've never had a fight end so easily for me, but then again it all of "That guy"s that actually WANT to play SSBB.
Also I hate Halo. The difficulty between story mode and multiplayer jumps so vastly that you'll feel like you've got a beat on playing the game in story mode because the developers made them so easy. I remember playing Halo 2 when I was sick one day on a friend's Xbox that he let me borrow one day though the problem was it didn't even keep me entertained long enough to get better, and when I decided to log into a game server and got my ass handed to me without so much as 3 kills. Really Halo to me is just imbalanced in terms of play styles, though this may be because that it's a console FPS and for those of you who've gotten used to playing FPSs on PCs then trying to manuver in Halo is like playing a Space Marine who's come out of Space retirement and hasn't gotten quite in shape again.
Again like my opinions are above Yahtzee's videos are really his opinions, though they are very well thought out opinions.