Not first, it'* a CoolerMaster WaveMaster rip off. Don't believe me? Compare them. I like black cases, I'd go with 4. But just mod it yourself if you don't find one you like. Did you check out Lian-Li? GREAT quality cases.
It'* a CASE. The case I have now is the smallest one that will fit a regular ATX board, that way when there was a LAN party I didnt have a 1-ton machine to lug around as well as monitor and other crap. It cost me 23$ shipped and came with a 300watt power supply(yeah it was cheap but it worked for almost 3 yrs before a SINGLE pin burned out on it.)
Get something tasteful yet stylish, it'* hard to find a case that'* not gaudy(aka: lit up like a x-mas tree with plexi siding). I like the one corvettecrazy posted.