Buy:
COD Black op's
12 can of stella artois
and look for your bedroom door and just have your self a good time
your set-up looks fine why not get new gaming pad, keyboard or sound system to go with it.
xbox wired controler nothing better tbh
My first choice would be a decent psu, I can't believe anyone didn't mention until the end of pg1. Yes it is a pile of cheap nasty crap. Get a decent psu along with a nice case, maybe overclock the cpu..
Good PSU and new case - providing you don't do anything stupid then these can last all your future rebuilds/upgrades.
I've had three cases (Coolermaster Wavemaster, Antec 900 and finally Xigmatek Utgard) and fell in love with my last (Xigmatek) as it was well finished and looks awesome and consequently all future rebuilds/upgrades will be in this until it breaks somehow!
Modular has nothing to do with braided cables.... It's about efficiency and and the way electrical sin wave is used by the psu....basically it provides safer stronger move efficient waves which cost you less in your bill.....