Newegg has the Rosewill Fortress 550W for $50 after MIR
on shell shocker today. Professional reviews are positive (should be for a 80 Plus Platinum Cert. PSU). Only caveat is that it's not modular. For the price, it's hard to complain. This PSU was on sale during black Friday weekend for the same price after MIR.
i5-3570K, ASRock Z77 Pro4-m, Asus GTX660 TOP, 120 GB Vertex 3 Max IOPS, 2 TB Samsung EcoGreen F4, 8GB G-Skill @1.25V, Silverstone PS07B