But for brilliant games, I will still replay them on Hard, e.g. last one was Deus Ex:HR, it was still challenging on the hardest setting, as in you could be shot dead in seconds with very few hits but it felt well balanced, unlike a lot of games where they just add more enemies and give them too many hit points.
Hardest/Expert.
Apart from the final round in Quake III. It's impossihard.