Sub-$600 (gaming) build advice

Alright, so it's been YEARS since I've considered a new build, and I'm no longer "up to date" on what's out there and what's available. Therefore, I turn this over to the experts - those reading, what are your thoughts on what I've been able to compile? I'm looking for something that I can play games on, CLOSE to max settings if I can't get there (I want it to be worth playing on instead of my PS3 or 360!), but also to hook up to my 42" HDTV to stream Netflix, watch movies, etc.

Approximate Purchase Date: Probably sometime in the early part of May, so 2-3 weeks.

Budget Range: As mentioned in the title, I'm hoping for $600 after rebates.

System Usage from Most to Least Important: Gaming, watching movies/streaming, surfing the Internet (though I've got an MBP that's two years old that works fine for that)

Parts Not Required: Mouse, monitor, speakers, OS (win7)

Preferred Website(s) for Parts: Newegg

Country of Origin: USA

Parts Preferences: I've listed below what I'm looking at, though I'm open to suggestions on all parts - this is just what I came up with based on prior knowledge and some research/comparison. I went with the i3 2100 after much deliberation and reading, I was originally looking at a Phenom II 955 (and still would if the savings are worth it!).

Overclocking: If necessary, yes

SLI or Crossfire: If necessary, yes

Monitor Resolution: 1920x1080

Additional Comments: I've included below what I was able to put together, as mentioned; this is by no means what I am expecting to be perfect, but it did fit within my budget.

CPU: Intel Core i3-2100 Sandy Bridge 3.1GHz LGA 1155 65W Dual-Core Desktop Processor BX80623I32100

Motherboard: BIOSTAR TH67+ LGA 1155 Intel H67 HDMI SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard

Video card: GIGABYTE GV-R577UD-1GD Radeon HD 5770 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card

Memory: G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory Model F3-10600CL8D-4GBHK

Case: Rosewill CHALLENGER Black Gaming ATX Mid Tower Computer Case

PSU: Antec BP550 Plus 550W Continuous Power ATX12V V2.2 80 PLUS Certified Modular Active PFC Power Supply

Optical drive:LG CD/DVD Burner Black IDE Model GH22NP21 - OEM

I'm also planning on some Arctic Silver Thermal Compound.

So, am I on the right track?