Depends on your CPU and cooler. What do you have?
I'm rolling with AMD Phenom II x6 1090t (Stock Heatsink/fan), 3 120mm Fans (two bottem front, 1 top back), 1 200mm Fan (Top of the case).
I'm thinking about adding (I don't wanna worry about how hot this stuff gets while im gaming but im also not ready for liquid cooling):
For the side fan - (Currently not one but there is a place for one)
UPDATE
Rosewill RFA-120-BL 120mm 4 Blue LEDs LED Case Fan
Item #: N82E16835200049
Return Policy: Standard Return Policy
$5.99
Instead of:
APEVIA CF12SL-UBL 120mm Blue LED Case Fan
Item #: N82E16811998121
Return Policy: Standard Return Policy
$7.97
Below the Radeon 5970 2g -
EVERCOOL SB-F1 PCI Slot Case Cooler
Item #: N82E16835119065
Return Policy: Standard Return Policy
$8.49
Front top of the case under the Opt Drive - (Only two side by side pulling in, the deal for 10 is just so good!)
MASSCOOL FD08025S1M4 80mm Case Fan
Item #: N82E16835150007
Return Policy: Standard Return Policy
-$1.00 Sale
$19.90
$9.90
($0.99 each)
Above the GPU -
VANTEC SP-FC70-BL 70mm PCI Slot Case Cooler
Item #: N82E16835888112
Return Policy: Standard Return Policy