I'm sticking with XP till 7 comes out. It doesn't use every last ounce of RAM (got 4 in there), but XP doesn't need all that either. XP 64bit is a good option as long as you're sure you've got your drivers covered. Most stuff is ok (nvidia, amd, intel, other big brands), but soundmax audio drivers can be hard to find. On laptops it's probably not such a good idea as they're specific hardware is not always supported. Vista is much better with 64bit driver support.
2/17/09 at 6:39pm