Neverwinter Nights. I still hold a great fondness for the game and can still find enjoyment, but the way it controls, especially after playing so much Dragon Age just feels so awkward to me. The character appearance options have not aged well neither but they were kind of weak even back then.
Wizardry 8. I can't even get past the character creation before I lose interest. I've always wanted to finish it, but I can't even really bring myself to start it anymore.
Civilization II. Honestly, at this point at Civilization game without clearly defined borders for the nations just feels so, incomplete to me. I just always liked territory outlines for some reason. Although I do miss having Elvis as my cultural adviser.
Command & Conquer. The only reason for this really is because there is no move and attack command, something I've grown far too used to in RTSs.
X-COM. I have to admit I only recently started giving this game a try, but as much as I want to get into it, the high level of micromanagement just turns me off of it. I love games with depth, don't get me wrong, just with X-COM I can't seem to find the patience for it.
Thief I & II. This one is kind of more my fault, in a way. It's not the graphics or anything, but rather the fact that I've discovered several ways to exploit the AI that kind of removes the challenge unless I play it on expert, but even then I can still exploit the AI if needed. Well, any AI that can be knocked out with a Blackjack that is.