If you can't tell by now, I am really in love (not -that- way!) with the K7D Master L from MSI. The board has proven to be as stable or even more stable for me than any other board that has crossed my desk, it does it with more features than any of those other boards, and it does it with a bit of pizazz.
The Master L carries just the right balance of integrated peripherals, "extra" add-on features, stability and tweakability for just about anyone's needs. For a production workstation, set everything to default and let it run without having to worry about stability issues. Home "hobbiest" machine? With multiplier, FSB and Vcore adjustments, push it as far as you can. In fact, I can't really think of a workstation role that the K7D Master L couldn't fill.
