Shadow of Rome.
Fuck saving helpless hostages with friendly fire on in a room full of endlessly respawning half tank half man enemies who have full body armour plus halberds and instant death traps and archers and... fuck.
I'd also like to un-nominate Dead Rising. The save system was designed to give the player a sense of responsibility and consequence upon death, and saving never takes any more than a few minutes.
Having said that, I can completely understand the frustrations with it, including feeling rushed by the six hour time limit, but it was designed that way. The sequel will at least have three save slots and co-op, so perhaps some people who were put off from the first may have a go at the second.