I just got a pound of late winter high mountain oolong tea from Seattle's Best Tea (506 S. King St., International District). It's absolutely amazing, the best of the last few years. Oolong is on the continuum between green and black tea; it can be lightly oxidized and come off more like green tea, or mostly oxidized and taste like a mild black tea.
We have a few new tea shops in town, but this little place, across from the old Uwajimaya space, has always been my favorite. Sit down and drink with the owner before you buy. She'll charm you into a half-pound of pristine, hand-harvested oolong before you even know what hit you. Going here makes me appreciate my ignorance about tea, and always helps me put my tendency to wonk out about wine in check. Whether you know anything about tea or not, this is a place to be at ease. By the end of the month, the first of the spring oolong will arrive, and it's supposed to be the stuff.