Sacrifice is on the must-replay list, and patched up doesnt require the disk.
It was a great game w/ some unbelievable spells (bovine intervention lol) but it was also quite brutal, i never finished it. Partly due to the system i was playing it on at the time was being chewed up by it, I hope it's one of those old games that run like a top w/ requirements a hundred times more than required.
My most painful pleasure? Hmm..
It may cost me some street cred here but think the original Baldur's Gate should get a mention as a fairly difficult game, i mean, it's not all THAT bad that ive thrown my hands up or anything - but it certainly is smackin me and my merry party around a bit lately, certainly moreso than any other recent RPG. I'll be doing great, have a lot of confidence built up, then suddenly i'm seeing the hand dissolving cinematic and I'm wondering "WTF??". I generally dont like to save that much, but I'm finding myself losing an hour of play after mowing thru several obstacles and suddenly wipe or lose an important member. Ive got Imoen cruising around, scouting everything ahead!
It's still totally enjoyable, if a bit frustrating at times.
I'd have to say one that spanked me hard, and i went back (and still go back) to it nonetheless is the original Ghost Recon. Man, doesnt matter what I do - *bam* suddenly a squad member down. I can spot every enemy, work out the perfect plan, creep like molasses, still someone catches a bullet. Sometimes i can get thru a scenario w/ whole squad intact, but it's rare. Granted that it's not all my fault, the ai is suicidal and blind at times, but youd think w/ how much Ive played it that I could master it by now. It's just a difficult, tricky game.
I wouldnt say that Gothic was that bad, but Gothic II gold fucked me up so majorly, to the point that I uninstalled it. I just didnt feel i was making any progress after a while!