I'm re-watching The Magicians with my wife, since she's never seen it. It's been long enough since I watched it last that I don't remember a lot of things that happened, so there's a lot of "I forgot got that!" moments for me, which is fun.
Currently I'm rewatching Stargate SG-1. It has held time surprisingly well. Lets see if I agree with concurrent watching of Atlantis when I get to those seasons, which I thought a little silly at the time.
Atlantis is a little silly, but in a campy way that never takes itself too seriously. SG-1 does a better job at keeping the tone pretty serious throughout, but with comedic intervals whereas Atlantis definitely tries for more humor. Both are really good though.
I love both, but I actually prefer Atlantis's ongoing series arc over the more episodic/season arc structure of SG-1.
Possibly unpopular opinion (?): Universe was a fantastic show that got cancelled right as it was getting really good. Stargate's answer to Voyager and Battlestar Galactica. Really wish we could have gotten more of it. With the way they left things, it's not too late to revive it if they can get actors on board. They can easily explain cast aging or not returning with the final cliffhanger.
Universe is my favorite, with SG1 close behind. I feel like Universe tried too hard to be Battlestar Galactica at first and the network wasn't impressed when it didn't hit it off like BSG. I would have loved another season.