I was always a Barbarian - duel wielding broadswords, whee! But while I found the game quite enjoyable for a while, Diablo 2 is one of the few games I literally got so angry at that I never finished playing.
Well that's not strictly accurate - I'd actually made it almost all the way through the expansion before some calamity or other struck my computer, and it was my second character, remade in the image of my first that made me so mad I swore off the game. See, I REALLY didn't like the bit where the game treated a single-player campaign like it was an MMO, making saving a non-existent gameplay aspect; if you wanted to save your progress, you had to quit the game, and any calamity that struck your character was thus permanent.
This was not usually a problem, but you only have to die once, die while trying to retrieve your corpse, log out in frustration so your corpse (minus all the money it was carrying) appears back in town only to find it's the corpse of your character carrying none of your actual gear because this is the instance of you that died the second time... to provoke a stream of extemporaneous profanity and greatly elevated blood pressure. Your stuff is basically who you are and the game just STOLE it by refusing to let me BLOODY SAVE MY GAME YOU BASTARDS RAAARRRR!!!!
Years later I tried to play the game again when I saw Blizzard had released patches removing the copy protection, but - through some odd quick of my hardware at the time - attempting to play the game would work fine for precisely 5 minutes, and then it would physically power off my computer. When it happened the first time I thought it was an isolated glitch, but times 2-4 illustrated that no, it was definitely the game somehow - Blizzard didn't want me to forgive the game after all these years it seemed.