Steam keeps switching out the deals daily as they are wont to do, so here's my picks for the day from the featured stuff. Today's theme is funny games, apparently, because all three of the recommendations in this post have a strong comedic element.
Overlord Complete Pack: $4.99 - I've only finished the original Overlord game (I'm stuck in Overlord 2 at a point that I doubt I'll be getting around without the aid of an analog controller) but I can vouch for the fact that these games are well polished, funny, and most importantly - fun. Rhianna Pratchett (Terry Pratchett's daughter) did the writing for the series, and the Pratchett sense of humor is very much present.
Magicka: $4.00 - I'm holding off on finishing Magicka until I can do it with some friends I've been playing with, but I would recommend it without hesitation. It's another funny, silly game, with a great magic system that has you crafting effects on the fly. Play it with some friends that you can both work with and laugh with for maximum enjoyment.
Worms Reloaded: $6.79 - If you've never played a Worms game, you've missed out on a uniquely ridiculous brand of fun. Trying to blow up your friends or AI opponents with exploding sheep, the Holy Hand Grenade and other ridiculous weapons while listening to silly banter on the part of the worms is great.