So my 2 cents. First off, The Flash is my favorite superhero OF ALL TIME. But even I did not vote for that being the best show. I will preface all of my remarks in that I am WAY behind, or have never seen, some of these shows because real life (7 year old boy/girl twins and my wife and father were both diagnosed with cancer last year) has had me preoccupied (rightly so, but still). So onto the shows:
Arrow - Loved the show when it first came out and, of course, it kinda spawned all these other shows so you have to give it some credit, but the later seasons just became filled with too much angst and brooding and Oliver making the same mistakes over and over and over... well you get the point.
The Flash - First season was AMAZABALLS!!! Henry Cavanagh is one of the most underrated actors out there and has done a marvelous job playing all the different multiverse versions of Harrison Wells. Simply underrated for that. After that, and others have pointed it out, it got a little timey-wimey and mopey. The worst season was when Elongated Man was introduced because he was so offensively unwatchable (referred to all the female characters on the show by their body measurements, etc. Thankfully the guy responsible for that horridness was fired and so to was Hartley Sawyer for his highly offensive sexist, racist and misogynistic comments). I have only watched up to season 5 currently but plan on watching season 6 and beyond because I still loves me some Flash.
Supergirl - I really liked this show to and have fallen behind on it for reasons above. It's good but could be better. I'm not a big fan of the Super's, especially Superman, but this show was done pretty well.
Legends of Tomorrow - This is the one I voted for. Season 1 was a bit of a struggle as I think the show was trying to "find itself" and I really like what they have settled into since. It is more on the "light" side of the DC universe and I find it refreshing and funny. They have no qualms about poking fun at themselves (like the crossover they were not involved in) and I just enjoy the show for what it is and I don't expect any more than that.
Black Lightning - Have not got a chance to watch it yet and would like to eventually.
Batwoman - Same as Black Lightning
Stargirl - I must really be out of touch. Didn't even know this was a show... I need to get out more.
Doom Patrol - Same as Stargirl. How am I this out of sorts?
Titans - Holy crap?!? Am I in a cave or something?!? I REALLY need to get out more. Or rather, in more, like where the TV is, because who keeps TV's outside? Oh right. Drive-In's. Damn you Baldur's Gate on Nintendo Switch eating up all my free time!!! Holy crap can you imaging playing console games on a drive-in screen...