[Coolzer]

That PSU needs to be upgraded. How powerful depends on the card you buy. Because you have a 1080p tv you'll need a relatively power hungry card.

Highend
Newegg.com - ASUS EAH4870/HTDI/512M/A Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Desktop Graphics / Video Cards

Midrange (i'm leaning this way...)
Newegg.com - BFG Tech BFGE98512GTXOCE GeForce 9800 GTX 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards

Low
Newegg.com - MSI N9800GT 512OC GeForce 9800 GT 512MB 256-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards