Dark Souls
Only 2 levels (Tomb of Giants & kiln of the first flame) and 2 bosses (Nito and Gwyn) left before I start New Game +, so far this game was a breeze compared to Demon's Souls.
Bosses are about the same difficulty, only Capra (= cheap) and Four Kings are noticeably harder than any of Demon's Souls bosses.The areas in this game however are A LOT easier, they might have 2-3 times the amount of enemies but you seem to be getting checkpoints every few steps (where demon's souls has some big levels with NO checkpoints).
Hardest part for me, so far, where those damn flying knifes in Sen's fortress, I'm bloody sure they wouldn't hit me and then.. they hit me and I fell to my doom, 20 times in a row.