Best GPU for 450W PSU ?

[Prajay Basu]

My rig :

Corsair VS450
i5 4440 3.1GHz (84W)
Gigabyte GA-B85-D3H Motherboard
BenQ GW2255 21.5 inch 1080p

 

[chris987]

that would be gtx 660 or R9 270