I guess again we are at what one likes in a game to decide and you can't overrule the preferences of people.  I happened to thought Assassin's Creed is good, but I hit a wall with it.  As for Crackdown, I wish there was more variety, but it came close to what I was looking for in a sandbox action title.  While more structured, I found inFAMOUS stepped it up more, and did what Crackdown did, but was better overall.  I am interested in seeing what is next with Crackdown 2.

On the other end, I found Earth Defense Force and The Outfit for the 360 both got panned pretty much around, but I really liked those.

So, I guess we get back to why the phrase "Your Mileage May Vary" is mentioned.  It is beneficially if people keep that in mind.  Of course, some things, like bad controls, is pretty universal. 

Bioshock - this game is not an FPS. I am prolly the only person on the net that hated it.
Fallout 3 - see reason above
MGS4 - I wouldn't blame the hype but the awesomeness of MGS1 and MGS3.
Gears of War 2 - Not as good as first one...more lame story less fun gameplay
Megaman 9 - too cheap to be fun to me. Internet disagrees

I think that, just maybe, taste has something to do with this.

Quality almost never supplants taste in regards to enjoyment.  Something could be the best thing in the world, but if you don't enjoy what the thing of quality is, then it won't be enjoyable, no matter how well it is done.

GTAIV=MASSIVE LETDOWN

It kept getting all those really high scores and everybody was talking about how awesome it was so I went out to rent it and it was TERRIBAD.

That hasn't happened to me.

In fact, it happened the contrary: I bought games that had poor reviews or that weren't A games, at least, just because I liked them.

Wild Arms - Not much hype but it was one of the few PS1 RPGs at the time by Sony and I thought I'd give it a try. It wasted 10 hours of my life.

RE4 - Too hard for me to bother.

REUC - There is no point in playing a RE on rails shooter for me. Way too hard.

Prince of Persia (Modern console) - It looked cool (very different than most games) but the gameplay reminded me of the first Tomb Raider in how bad it was. 15 or something years later and no where near enough progress for me.

Rhythm Heaven - Unplayable for me.

Empire Earth - Ridiculously bad in easy of use.

Exactly.  One man's trash is another man's treasure.

I got turned off on RE4 on the Gamecube because it was too hard, I couldn't even get past that first village.  Silly me ran right down the middle or back and died both ways. 

It wasn't until I got it on the Wii that I had the bright idea to avoid the villagers.  :-p

again with the number 4 twesterm lol