I hate a few, but I have reasons for them, so they're not irrational.
JRPGs (actually, I'd almost group all Japanese games into this): Mostly because I envision the fanbase to be mostly like this girl [http://www.youtube.com/watch?v=3xRSa5tMLUQ]. And the games always look the same. Androgynous whiny male goes on turn-based linear quest to find MacGuffin with annoying sidekicks. Insert lots of groan moments such as this [http://www.youtube.com/watch?v=-5FTJxfV3pc] into the game, since the afore-mentioned fanbase loves this shit and eats it like crackers.
Modern Warfare 2, Halo 3: Mainly because there's better shooters and these are super-popular for some reason.
Metal Gear Solid: Again, see JRPGs and also MW2/Halo 3. I played the one for Gamecube and it just sucked compared to Splinter Cell but people always say how awesome MGS is.
Wii Games: Again, see JRPGs. Also since waving a stick at a screen is now the only requirement needed to be a "totally cool gamer LOL". I can't wait for the tweeny stores to release "GAMURR GEAR", with shirts depicting classic characters like Mario being transformed into unfashionable clothes. Oh, wait... That already happened.