[Torture]

Here's a list of Graphics cards I found on Gamespot:
Nvidiafrom best to worst
GeForce GTX 480
GeForce GTX 470
GeForce GTX 465
GeForce GTX 460

GeForce GTX 295
GeForce GTX 285
GeForce GTX 285 for Mac
GeForce GTX 280
GeForce GTX 275
GeForce GTX 260
GeForce GTS 250
GeForce 9800 GX2
GeForce 9800 GTX+
GeForce 9800 GTX
GeForce 9800 GT
GeForce 8800 GT(Blizzard Recommended)

ATI from best to worst
ATI Radeon™ HD 5970 Graphics
ATI Radeon™ HD 5870 Eyefinity 6 Edition Graphics
ATI Radeon™ HD 5870 Graphics
ATI Radeon™ HD 5850 Graphics
ATI Radeon™ HD 5830 Graphics
ATI Radeon™ HD 5770 Graphics
ATI Radeon™ HD 5750 Graphics
ATI Radeon™ HD 5670 Graphics
ATI Radeon™ HD 5570 Graphics
ATI Radeon™ HD 5550 Graphics
ATI Radeon™ HD 5450 Graphics
ATI Radeon™ HD 4870 X2 Graphics
ATI Radeon™ HD 4890 Graphics
ATI Radeon™ HD 4870 Graphics
ATI Radeon™ HD 4850 Graphics
ATI Radeon™ HD 4830 Graphics
ATI Radeon™ HD 4770 Graphics
ATI Radeon™ HD 4600 Series
ATI Radeon™ HD 4550 Graphics
ATI Radeon™ HD 4300 Series
ATI Radeon™ HD 4200 Series
Radeon HD 3870 X2
Radeon HD 3870(Blizzard Recommended)

For reference my roomie has 2X 1GB 4850s and runs it on Ultra so I assume the 5450 would be decent.