I think I hate it when I have to do anything in an FPS besides kill everything and get to the end of the level/
Granted I haven't played Portal, but I couldn't get too far in Metroid Prime because there were platforming parts in it which I ultimately decided was bullshit for a first person view. Not being able to see your lower body makes pretty much every jump a leap of faith.
Maybe I'm just spoiled by Mario type platformers where you could see your entire body, look around if needed, and judge your jumps accordingly.
And it's not just platforming that bugs me in FPSs. Any FPS where I have to search up and down a boring level for a stupid key while every room and hallway looks the same will instantly earn my hatred. Of course, I'm really just thinking of my bad experience with Wolfenstein 3D, a game that would have been better if either I didn't have to find keys or the levels were actually fun or interesting to navigate as opposed to the same blue corridors level after fucking level.
So I guess FPSs just aren't for me. Then again I did play Halo and I thought the controls were good, and despite the fact that some levels were boring and monotonous, all I had to do for the most part was kill everything and get to the end so backtracking was minimal. But that game had no bosses so when I finished it I had an empty "that's it?" feeling from it. Perhaps that's why so many people bought the sequel. Not to mention the weapon selection was shit. The only thing that stood out in my mind as both interesting and useful were sticky grenades. The Needler was an interesting concept, sure, but far less useful than the assault rifle you get at the start of almost every mission.
Although I do have to admit that I liked Duke Nukem 3D. There was some key card hunting in that game but the levels was interesting enough to warrant a little bit of exploring. Plus the weapon selection was good. So I guess that's the only FPS I've ever really liked. But that's probably because I'm mostly a console gamer.
I'm sure I'd be more into the whole FPS thing if I had a PC gaming rig. The bit of Duke Nuken 3D that I've played was on my brother's computer. I did try playing the N64 port but I had to put the controller down after about 30 seconds of gameplay because the controls were fucking terrible.