Here is my htpc setup.
Antec minuet case
AMD x2 4200+
1gb ram
Asus M2n-HDMI mobo
Seagate 250mb sata2 drive
Gyration universal remote and air mouse.
Cost me less than $400. I have a 25mbs internet connection and DL watch and burn 1080p errr stuff in .x264 format.