My first SteamGifts giveaway.

Dungeons of Dredmoor is a very cheap (4.99 USD) Rogue-like game with a huge amount of humor and gaming references, including Sid Meier's Alpha Centauri ("Please don't go. The Diggles need you. They look up to you." when randomly hitting the exit game button), Dwarf Fortress (quite a lot of item/resistance descriptions), and many other games.

While the humor alone is enough to carry this cheap title, DoD excels in the gameplay aspect as well. You can pick seven skills from a selection of 34, including Last Choice (if you want to keep the same skill selection as your last character) or Randomize. Such skills include Mathemagics, Viking Wizardry, Necronomiconomics, Vampirism, and many more.

For a more in-depth look into Dungeons of Dredmoor, TotalBiscuit made a first impressions video: http://www.youtube.com/watch?v=pyTfUnnxZV4