Bioshock: the gameplay is just horrible. The atmosphere is fine, but everything else just sucks. I don't know what people are talking about when they say it had a better plot than the sequel. Both barely hold together with how incredibly loose the logic becomes.
Team Fortress 2: Why do all my weapons suck? What's that, I can unlock better ones through either random luck or getting achievements? I see, but both of those will take hundreds of hours, of which I will have to spend disadvanteged by limiting my options. Is there another way? Oh, paying obscene prices? More than twice the price of the game itself for all the extra equipment you say? I see, fuck you Valve.
Half-Life 2: The game got a free ride due to its technical achievements. Once other games did it and I could see through them to the game itself I found it very generic and mediocre. Plot was pretty good though, at least good enough that I like to know how it turns out!
Any old school CRPG: The combat system of click enemy, pray stats are higher, or if I'm really feeling like wracking my brain, spam abilities, take potions, repeat as necessary, is incredibly dull to me.