Monkfish Acc. said:
The hardest difficulty on Far Cry 2. Every encounter was dreaded, in the end I had to drop it by a level. The difference was massive.
Infamous isn't too bad, but you will definitely learn to fear those road patrols... so much lost progress due to the fact that they can often kill you faster than you can hide somewhere. Stealth is basically the only option.
One of the hardest things I've done recently is completing the Flopside Pit of 100 Trials from
Super Paper Mario. The first one is pretty tough, but unless you level grind like crazy the second one requires a minimum investment of at least an hour, and there is a very good chance you will only make it to floor 80 or so. I died twice on the final boss before completing it, and it took me a good six or seven tries... not the hardest thing ever, but incredibly frustrating due to the repetitive nature of the task.
Mass Effect is also ridiculously hard in some places if you play on the Insanity difficulty, especially with certain character classes/party types. There are some enemies in particular, like Krogan, that not only have massive amounts of health, but also are able to become invincible for several seconds, regain all their hit points upon death every 60 seconds or so (meaning you have to kill them a minimum of two times), and can kill you with one or two melee strikes and have a nasty habit of charging you. There's two parts especially, the first on Therum and the second on Vermire, where due to either their numbers or environmental conditions, I had to fight them a good 20 times over just to win... oh, and don't forget the unskippable cutscenes that happen before those fights. Thanks, BioWare.