Besides finding some really sweet loot (who doesn't love that?), here are some things that give me the warm fuzzies inside:
1. I love AoE effects. Zombie summoners are prime candidates. Charge into the middle, drop anchor and shield turn them to butter. Or Blademaster blender abilities. Or Evoker Bone abilities. Bone shards is really fun, even to blow up a lot of crates and boxes.
2. Phase explosions! Glowing gibs yay!
3. Blademaster surges. So fun to haul ass around the map and crit everything into tiny pieces.
Honorable mentions: Grenades! Brom's Curse + Drain Energy or Venom Armor. Talking to Lucious and 314.
How about you?