Okay, I know you specified under 120$, but I had to pitch this one forward. It's what I bought myself last week.
Cooler Master HAF 932
view here:
http://www.amazon.com/Cooler-Master-Advanced-Tower-SuperSpeed/dp/B001EPUQAE/ref=sr_1_1?s=electronics&ie=UTF8&qid=1316966656&sr=1-1
Very roomy (can fit 3 top of the line and top of the size chart GPUs with ease), fits just about any type of motherboard though you'd want to go for ATX in this baby.
Comes with 4 fans (3 of which are huge!)
1x Front 230mm fan (which shiny red led for that "I'm pure evil" look)
1x Top 230mm fan
1x side 230mm fan
1x rear 140mm fan
Supports future water cooling, if you choose to go that path.
Has no-tools-required HDD slots, meaning you won't have to fidget around with screws just to install or extract your HDDs (simple click lock mechanism).
Has a pretty window to look in on your internals and extranally it looks like the military recycles the stealth bomber into your PC case.
HAF stands for "High air flow" and it seems to provide just that.
Goes for 139$, which is an extra 19$ over budget but totally worth it in my opinion.