Too Human. Decent story. Freaking impossible to play.
Mass Effect on PC takes a lot of getting used to, especially if you only have a track pad. Swapping between installments will have you throwing grenades in celebration after battles trying to put your weapon away, too.
Virtually every Japanese PC game as @Jackho pointed out.
I also had an interesting time with Vanquish, though to be fair part of that is just the game mechanics themselves of jetboosting around in a third person shooter. It's also worth noting that it's a Jap game.
TenchuZ's controls were unwieldy at best. Great for melee, absolute ass for ranged anything.
I also have an interesting time with any game that doesn't have me click a stick to sprint. Mass Effect's hold A button, Skyrim's hold ... left bumper? TenchuZ's whatever ungodly button you set it to... Eh, sprinting in games is just weird and I've grown accustomed to that.
Let's not even talk about the driving mechanics of Mass Effect's Mako, Saints Row's shitty drive by shooting controls, or, God forbid, Skyrim's unwieldy fighting on horseback.
And then there's the obvious QWOP.