This is starting to sound like an Epifanes stockholder's meeting, but I've always been highly pleased with their
varnish, ease of application and longevity of the clear gloss. I've been most successful with starting at bare wood, building up 10 - 12 coats, with 2 - 3 new coats every spring -- I get about 10 years between stripping this way. (But it is absolutely necessary to follow the instructions to the letter.)
Interior-wise, I'd recommend Epifanes again. I recently took the teak
hatch trim down to bare wood on all 6
hatches on our Mason 44 and built it back up with 6 coats of clear gloss and 2 of matte. Looks terrific and matches the exemplary finish on the rest of the interior teak.
Oh yeah, I used to be a die-hard Chinese bristle brusher. But I've converted fully to foam brushes. Much easier. Much faster. Much cheaper.