Loudest, most effective, cheapest case fans?

wow... weird requirement, i gather you basically mean the best cheap case fan, and added loudest to make sure we went for something cheap that moved air, with no consideration for noise?

what size?

nm... here is some just by using manufacturer's specs (understand fan manufacturers lie out of habit about both CFM and dB).

120mm -
bgears b-Blaster 120 120mm Case Fan - $9.99 (they claim 103CFM)
Dynatron DF1212025BM-3/4G 120mm Case Fan - $9.99 (they claim 80.6CFM)
140mm -
Prolimatech PRO-RV14LED 140mm Red LED Red Vortex 14 LED Case Cooler - $11.99 (they claim 87CFM)
Rosewill ROCF-11003 Hyperborea 140mm Case Fan - 12.99 (they claim 89.5CFM)
200mm
COOLER MASTER Megaflow 200 R4-LUS-07AR-GP 200mm Red LED Case cooler - 14.99 (they claim 110CFM)

hope that helps. i've no experience with any of those so i cannot comment. Generally speaking i mostly deal with the best CFM/low noise coolers i can find
 
Nah, I just like the noise when your PC is on for some reason. It just feels so good to come home after a long day and fire up that mini-airplane hangar in your room.