Yup Asus and Abit tend to be a cut above the rest - but Gigabyte are good for value and aren't too far off in quality terms.
I was always against using Jetway boards (as I thought they were cheap and rubbish) but I tried one (The Jet830Ultra) and was very pleasantly surprised. Had onboard sound+graphics, but also had an AGP port and plenty of spare PCI slots so you could add the best sound and graphics gear without too much bother.
Best of luck with your upgrading,
Regards,
Mike