Computer Build - Compatibility and Quality Questions

The Build:

PSU: COOLER MASTER eXtreme Power Plus RS500-PCARD3-US 500W ATX12V v2.3 Power Supply ($45)

GPU: ASUS EAH6670/DIS/1GD5 Radeon HD 6670 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready Video Card ($93)

Case: COOLER MASTER Elite 311 RC-311B-BWN1 Blue Steel / Plastic ATX Mid Tower Computer Case ($45)

HDD: Western Digital Caviar Blue WD1600AAJS 160GB 7200 RPM 8MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive ($65)

OS: Microsoft Windows 7 Home Premium

RAM: G.SKILL NS 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9D-4GBNS ($24)

Motherboad: ASRock 970 EXTREME3 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX AMD Motherboard ($80)

CPU: AMD Athlon II X3 450 Rana 3.2GHz Socket AM3 95W Triple-Core Desktop Processor ADX450WFGMBOX ($78)

Optical Drive: ASUS 24X DVD Burner - Bulk 24X DVD+R 8X DVD+RW 12X DVD+R DL 24X DVD-R 6X DVD-RW 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM Black SATA Model DRW-24B1ST/BLK/B/AS - OEM ($17)


Other Details: I will be looking to be playing games such as Minecraft, Diablo III, and Skyrim on lower settings. I will be playing on a 1600 x 900 resolution.
I want to make sure that this setup is compatible, and that the gpu is decent for it's price. I'm willing to spend like $10 more on a possible better GPU. Thanks in advance.