I'm only using Captains who are, were, or will be regular characters:
Kirk (TOS)
Picard
Pike
Saru
Sisko, Janeway, and Archer all had to make choices that I think work great for dramatic purposes but I personally find to be questionable, if I'm being objective.
Georgiou in the first two episodes of DSC would've been on this list, but her glaring flaw of promoting Burnham too fast was a fatal mistake. Lorca... he's a crooked bastard which, again, is good for drama but takes him off the list. So that leaves Saru for the #4 spot.
"Where's Burnham on your list being the big Discovery fan you are?!" All we've seen her do as Captain so far is say, "Let's fly!" I'm pretty sure I think she'll be great, and no doubt she'd be in my Top 4, but we haven't really seen her as an official Captain yet, so I can't include her in this list. I'm not counting anything before the promotion because stepping up to an occasion and doing the job on a regular basis are two different things.