I've heard many tube amps but the Single Ended Triodes ( S.E.T.) are my favorites. They only make a few watts and require high efficiency speakers but those few watts are just magical. I hope to have a 300B someday but for now I'm pretty happy with my modded MiniWatt. I can't wait to read the reviews on the new MW below.
http://www.aloaudio.com/store/index....roducts_id=401