For my favorite episode that's generally underrated, that's a no-brainer for me: Horizon. My favorite overall ENT episodes are In a Mirror, Darkly (both parts), followed by Azati Prime.
Terra Nova and Silent Enemy: both are clunky, with some major writing issues, but do a lot to set up the mood of the series as a whole. I would even suggest that they set up major season 4 episodes: the Romulan trilogy and Demons/Terra Prime. Favorite overall: Cold Station 12.
I did enjoy "Silent Enemy" a lot when I watched it, but like you, I too agree that the writing could have been more taut.
Desert Crossing is funny when they bring up his jailbreak of a few episodes prior. Johnny Archer has a reputation now, and when his trak-ball playing friend finds out he ain't really that tuff he detains Captain Archer til him and Trip Tucker are able to get away and craw across the desert. They make it to that little building then turns out they are bombing the shit out of it when the show ends with the shuttle craft coming to pick him up. Archer does one thing one week, then next week does the exact opposite. Gotta love these kind of episodes that are great for mindless just got home from work and I'm tierd tv watching. No thoughts allowed here.
"Civilization" has always been one of my favourite ENT episodes, and is one I return to fairly regularly. I particularly enjoy Diane DiLascio's performance as Riann.
Is that the episode where T'Pol says there are life-forms on the planet, and Trip later adds with a child-like exuberance there is 400 million? If so, I love that part, and ultimately the episode as well. Trip's reaction, to me, encompasses what Enterprise was about.
Rogue Planet. Yes, I get that the science is completely wonky: planet unmoored from any gravitational pull. But I do love the idea of a manifestation of something Archer cannot reach/have/find, which provides an excellent reason for him to become an explorer. I love the gentleness with which Trip and T'Pol handle Archer's crazy. They never see this apparition, but they go with it and help him find a solution to the drayjin's plight. I love that. And the conversations between Archer and the drayjin are so . . . sad.
"Doctor's Orders"-I know its a shameless rip-off of "One" but Phlox is my favorite ENT character and he was given so little to do on the show that a whole episode devoted to him was really enjoyable.
Agreed, I love a whole bunch of Phlox. I love all the Phlox stuff in ANIS, wish it had just been him in that sickbay!
Another vote for "Civilization". I first saw it in first-run, and it was the first episode of the series I actually liked. It felt very much like a TOS story, and I thought they were starting to find their footing in the series.
I recently just watched this episode, and it was the first one in the season where I felt the writers got Enterprise right.
I also loved The Seventh which is disliked. Great atmosphere, insight into Vulcan secret service shenanigans. And I like that we see Vulcans deliberately living outside of their tightly controlled society on ENT, this being another example. Sure they're all shitheads but it's still interesting.
TATV No, not really, 'Bound' was great fun. As folks mentioned earlier 'Civilization' was very TOS in feel. Also, 'Strange New World' was great for the characters under stress. I very much liked having no monster of the week, just the crew dealing with each other under the effects of the pollen. Great episode that used the various characters talents and weaknesses to good effect.