Games I recall of the top of my head......
Addams Family-2 or 3 days-never wanted to play an intertia based platformer since!!
Leisure Suit Larry 2-only missed by one point & without any solutions to help-this kept me replaing 24/7 for a few weeks.
Opertaion Stealth-As has been mentioned elsewhere, this game is a complete b****** with the "arcade" sections to finish-never again.
Silkworm-the copy I'd had actually zapped the official cheat & didn't have any other-not only did I finish it, I did so without the benefit of Autofire-my hand & wrist suffered RSI for days!
Heroes of the Lance-one crap arcade game & a travesty on the wonderful H.O.T.L DRagonlance triology.
I'm sure thee's others but can't recall off hand!