Best? Probably "Duet."
I'd have to think about worst--there are a few groaners.
I think Duet is the best as well, though I also like Drumhead, that would be my second favorite.
The worst has to be A Night in Sick Bay, where Archer acted like a childish lunatic for the whole episode. Good bottle episodes forgo special effects and focus on interesting situations and character studies, bad bottle episodes seem like pointless filler and have the characters involve in insipid plots because they couldn't get the budget to do something better.