One Awesome recomendation:
Phanteks Enthoo Pro.
It is one hell of a case, only $99.
Too cheap to be good? Well, you're wrong.
This case is actually a full tower, and is actually cheaper than some cases that I considered buying, like the NZXT Phantom and Fractal Refine R4.
It has all of the features from a case around $200, like Phantek's Primo without keeping the price high. It has great watercooling capabilities, as well as air cooling, with included 200mm fan and 140mm too.
Dust filters are all included, and to make things more fancy, there is a PSU bracket to cover your cables to have an elegant, hassle-free looking case. And on the back, are already pre-installed velcro ties to put your cable around, for easy rerouting of cables.
And I totally recommend you to follow SR-17 and MagicalWallaby's advice and take the Enthoo Pro.
Here is a review from a popular hardware reviewer, Hardware Canucks:
http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/66255-phanteks-enthoo-pro-case-review.html