DIABLO(I,II,III)

I haven't played Diablo I at all. I played the second one about 20 times, mostly as a Paladin. I completed all difficulties (the only annoying thing is that in my Diablo II, I can't complete the 4th quest in the first act and the 2nd quest in the 4th act; the game just crashes when I approach the blacksmith). It was so frustrating when I deleted all my characters after reinstalling Windows. My Paladins were: Richard - level 90, Jenya - level 69, and Knight - level 48; all the others were weaker. I don't quite understand the point of the Moo Moo Farm (secret level). I came, killed the cows, and then what? Overall, it's a great game. I hope Diablo III will be released, although I understand that it won't be soon, as Blizzard already has a lot on its plate.