Games that try too hard to be mature.

[Reasonable]

Depends what you mean by mature. For me, despite all the high ratings and concerns over gore, etc. games likes Gears, Army of Two, Modern Warfare, etc. are all far from mature. In fact, I'd argue most are actually fairly childish.

Mature for me means adult context and themes explored in an adult way. And really, certain themes aside, that doesn't even mean it has to require violence or language.

Heavy Rain looks like it might get it right, but I'll reserve judgment until I play it. After all, QD's last title started very well and looked like it was going to handle mature themes well, then went to hell in a hand basket from about the half way point in.