Halloween or Fear Itself more interesting and immersive, and more creative, though I love both.
Lessons or The Freshman I admit this is a close one, despite my not liking s7 on general principle. I think if Lessons had been tweaked differently without the rest of s7 that I could've chosen differently.
Him or Bewitched Bothered & Bewildered BBB is more connected to the other eps and characters better and the show was more exciting back then. Despite Buffy's rocket launcher scene, the s7 one just seemed like a rehash of BBB, and it raised questions about characters I didn't care for, unlike BBB (and being s7, worse was to come).
Earshot or Hush ok, love both of these, but Hush is one of the few I see as much better than Earshot.
The Body or The Gift I wish it weren't true, but The Body, which I don't uphold as perfection as many do, still had a better payoff and investment from me than The Gift. Not that I hate the latter.
Villains or Tough Love Villains is too far into s7 to even have a chance with me. Tough Love still had me invested in the characters.
Enemies or Innocence Seems more important to the arc and I cared more, whereas Enemies was more of something that just had to happen so they could go forward, and was a bit too...convenient (like having the shaman owe Giles).
Family or New Moon Rising Family was good and had a happier ending (and I love the miscast spell), but NMR explored the characters more with higher stakes and unexpected turns.
Also, Family just begs some questions never answered, like how other witches had been controlled (and why did they bother, there was surely something else going on there that begs an explanation) along with how Spike's chip is more magic than tech (if that microchip could truly tell the difference between human and demon, then a much larger device not buried in the brain of a vampire should be even more effective than Willow's spell to find demons). I'm geek enough for it to irk me.
This Years Girl/Who Are You? or Five by Five/Sanctuary Both SMG and ED got to show that they could play more than their characters, and was overall better...and while both had a sad ending, at least the 2 eps on Buffy didn't seem as contrived (like Buffy walking in just as Angel hugs faith, without so much as a phonecall if she really wanted to warn him, at least they could've had Cordelia call Buffy to let her know, then it wouldn't feel so contrived) and Buffy didn't look so bad. I was also just more invested in the Buffy two-parter, even if I came to like Faith more by Buffy season 7 (which has it's roots in 5b5/S).
Chosen or Not Fade Away this one was VERY hard for me, but I finally went with NFA as the deaths were at least given proper attention...and the "return to their roots" felt more real rather than trivial call backs (like "the Earth is doomed") in Chosen.
Becoming or Graduation Day another hard one, I went with the latter as I'd have been content if that was the end of the series (even though I know I'd have said there should've been more seasons).
The Prom or Once More with Feelings the ending for The Prom wins it, primarily with the Class Protector Award, and also Xander's surprisingly mature kindness to Cordelia, which Cordelia gracefully accepted (though I'm glad she didn't get back with Xander).
Something Blue or Tabula Rasa SB was just more fun while also making me care more, and it helps that I still liked Willow a lot in season 4, more so than s6.
Restless or Nightmares This was a hard one for me as Nightmares was fun cheese (with no cheese man!), but Restless explored the characters more and also kept the "magic has consequences" rule that they used to have (though pity they'd have to retcon it later, like the First Slayer being able to speak without aid in the next season).
Conversations with Dead People or I Only Have Eyes for You CWDP is the ultra-rare s7 ep that would beat out most eps, but right now I had to go with the latter as it has more of a creepy horror theme (and also referenced again in later eps), and I have to give it bonus points for the very end (that including Spike standing up from his wheelchair).