Orcs Must Die!/YMMV

Awesome Music: The battle themes will get you pumped to make orcs die, especially this one.
Catharsis Factor: Giant tightly packed army of orcs, meet fireball. Or Chain Lightning. Or an entire hallway of traps. Or a giant pendulum mace. Or smashing ceiling. Or acid pits. Or...
Demonic Spiders: It's in the job description for Gnoll Hunters, who directly attack you instead of going for the rift.
- If you're going for a five-skull ranking (which requires that you let NOTHING through the rift), Kobolds can quickly become this. They hopelessly outrun most traps and Paladins. You'd better hope the archers stop them if you're not around to do it yourself, or spend a ton of cash laying down Grinders and Brimstone (and then keep an eye out anyway to make sure the little buggers don't overwhelm them with sheer numbers).
Funny Moments: The Apprentice dancing when he completes a level. Never mind the gravity of the situation- he's loving every moment taking his enemies down.
Goddamned Bats: The Fire Babies. They are slow, do little damage, and die in one hit, but they fly, they are small and hard to target, and they come in big numbers. They are not much a threat on their own, but their flight means they have to be dealt with sooner rather than later, distracting the player from other threats they might be focusing on.

Back to Orcs Must Die!