Best case for gaming under $100

Corsair 400r or 300r
Fractial Design Arc Mid R2. I have the Define R4 and love it, but it is my file server case. For gaming with big GPUs, the Arc Mid will provide better airflow.
NZXT Phantom 410
Rosewill Blackhawk (not as nice as some of the cases listed above but still worthy).
 


That is not the front front intake fan, that is for an additional pivotable fan mounted to the hard drive cage.
Yes he wont be able to use that fan with a long GPU, but that is a fan that no other case has anyways.
The case still has 1 included 120mm in the front and 1 additional 120mm slot.

As far as a window, the OP did not mention any requirement of a window which is a purely cosmetic "bling" feature.
 
It is an "ok" case, it is not on par with any of the cases listed by myself or anyone else on here.

Less fan slots/options, less cable management features, hard drive bays go front to back and not side to side, does not include 2.5" adapters or quick release hard drive trays, and no USB 3.0.

This is basically a decent entry level case on par with a NZXT 210. I personally would rather take a Rosewill Challenger for $40 (when on sale) over this case. The $40 version does not have usb 3.0 either, but better cable management, and other features.