I find the steam port of all the classic Doom games (Ultimate Doom, Doom 2 Hell on Earth, Final Doom etc) To be horrible, utterly bad.
Classic Resident Evil games I find to be rubbish ports (1-3) Too awkward for my liking.
Resident Evil 4 was pretty woeful too.
Saints Row 3 at times feels to be bad. Yet, other times it's awesome.
Halo 2 for the most part was a horrible port for a long time. Some were lucky and got it up and running smoothly, others sadly..
Darksiders 2 isn't all that bad, but at first the control mapping feels awkward as hell. (Awesome game though)