I don't know if that 380W PSU will be able to handle that video card (it's probably dual +12V rails). The case only has one fan, so it'll get hot. The Caviar Green is a slow, tri-platter(?) drive meant for bulk storage and it shouldn't be used as a system boot drive. Here's what I'd do instead:
Athlon II X3 435 - $75
ASRock M3A770DE - $60
Cooler Master Centurion 5 - $50
Sapphire Radeon 4850 - $100
Western Digital Caviar Blue 500GB - $56
Corsair 450VX - $60 after MIR
4GB Patriot DDR3-1333 Memory - $97
Samsung DVD Burner - $25
...which goes something like $20 over the $500 mark, but which gives you a better case with two fans and toolless mounts, a much better/more reliable PSU with a single +12V rail and 5-year warranty, and a fast single-platter boot drive. To go under the $500 mark you could easily drop down to an Athlon II X2 240, which would still enable you to squeeze playable framerates from most games at 1680x1050 or lower.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
