The best episode of Enterprise is E2.
It is one of the best 3 episodes in all of Star Trek.
BOW BEFORE IT.. and include it in your lists full of drab pineapple cakes!
My personal favorite is "Observer Effect," but "E2" is in my top 5, along with "The Forgotten" and "Twilight." All essential viewing, IMHO. As well as anything with Jeffrey Combs.