Major game series' that you can't get into
Halo: Haven't played either one on X-Box. Played the PC demo for 10 minutes and disliked it. I played lots of Jedi Knight and BF1942 online, but FPS games in single player don't do it for me, especially with a controller.
Metroid: I like my games more fruity than not. Very rarely does something with a gloomy, dark atmosphere interest me. It didn't help that I read about escaping within a time limit after beating Mother Brain. I hate that kind of pressure. A few years ago I tried the NES rom and enjoyed it. I'll have to give the 2D games a fair chance in the future.
Gran Turismo: The only thing I care about in the world of cars is leg room. I've played the demos for 1 and 3 and found the racing boring compared to Sega Rally, Mario Kart and many others.
Soul Calibur series: I'm only into 3D fighters casually. I really liked Soul Blade and Soul Calibur had some great extras, but I never figured out what made it the "best fighter ever," especially since I hardly heard praise for it when it was an ugly system-12 game for a year and a half before.
Grand Theft Auto: Jack of all trades, master of none. What the games attempt to do is very impressive, but there's so much crap and frustration to deal with.
I'm sure I'm missing some...