CPU: Personally I think 64 bit processors are a waste of money if you don't have a need for a 64 bit processor
If you are just doing games/word processing/internet browsing/etc, you can probably get more bang for your buck with a Pentium D (the AMD dual cores aren't quite as good imo, but that could be biased
.
Mobo: good pick!
Memory: hard to go wrong with memory
Optical drives: I could care less
Case: If you can, its usually better to get a PSU-less case and buy your PSU seperately. A lot of the stock PSU's are crappy, especially with a cheaper brand like Aspire.
VideoCard: I have a hard time agreeing with getting non-ATI/NVidia manufactured cards simply because they tend to not be supported nearly as well for cutting edge games. MSI is a good choice if you must though.
HD: decent, but if I remember correctly its one of the noiser drives (if you care)
If you are looking to cut down on costs, Its easy to find hard drive and memory deals on slickdeals.net