ok, you can go a bit cheaper on all of this
Get the AS Rock 880 Motherboard: $59.99
+1. ASRock has always done well by me.
X2 250: $59.99
Meh. To save a buck, ok, but I'd probably choose the 260 at least, the X3 445, or X3 740BE (plus a HSF) if budget allows.
4 GB G.Skill DDR3-1333: $59.99
+1. I haven't bought a lot of it, but I've never had to return a G.Skill stick.
1 TB Seagate 7200.12 drive: $54.99
+1. Not remarkably slower than the F3.
Seasonic 300W PSU 80+ Bronze: $39.99
-1. Great PSU for an office PC, but limits any possible GPU upgrade. A $45 380W Antec Earthwatts will power a HD5770.
Rosewill microATX case with 1 120mm fan back: $29.99
+1. The Rosewill cases are plain but functional, and I've never run into a QA issue on any of them.
LG DVD Burner: $16.99
Nice price, even with changes.
Edit: "possibly light gaming" to me implies that a HD5670 would be sufficient, but it would depend on the title(s), resolution, and desired settings.