SATA makes the inside of the case easier too work with (due to smaller, neater cables) so i would recommend those if you are going to be inside your case a lot, however if not then as above, IDE stuff is plug and play.
SCSI is just expensive when a striped SATA RAID 0 will do the job just as well (as proved by several large graphics/video companys in their systems) and its a hell of a lot cheaper!!
AMD 2500+, 512mb Mem, 160GB (2xSATA 80GB in RAID0 array), K7N2G-ILSR (using on-board graphics and sound (for the moment ;-) ))
How many windows \"errors\" can there be??!!!