Diablo 2 is probably the childhood game for most of us here. What's your favorite hero class? Mine's the Necromancer; nothing says AWESOME like having an army killing everyone for you, while you just stay on range to cast spells and curses to make your minions more effective in battle. What about you guys?
Necromancer, easily. I'm a huge fan of pet classes in videogames, and the Necromancer in Diablo 2 is easily one of the most fun, compelling pet classes to play in pretty much every game. There's almost nothing as fun as having a giant undead army just kill everything.
The paladin is a good choice. Pretty much every paladin build is overpowered and not too hard to play. The hammerdin dominates in pvm and can easily hybrid as a smiter if needed.