I just finished a rewatch of DS9 recently and absolutely loved it.
I tried TNG but ended up skipping a lot of episodes, there are some classics but there's a lot of dross as well. It also hasn't aged that well IMO.
I also tried VOY but gave up after a few episodes, in no time I remembered all the things about it I didn't like, the main ones being bland characters and technobabble to solve perilous situations.
If you like a bit of TOS, have a look at Star Trek Continues on Youtube.
It's a fan film series (I know, I know) but unlike others it's done really well. Some of the acting is not the best and not every episode is a gem but overall I really liked it and think, that unlike any of the other fan made stuff, they really nailed the production. The sound, lighting, camera angles, music, all straight out of TOS.
My favorite episode was when they did their "mirror universe" episode as a direct sequel to the TOS episode "Mirror, Mirror" in that it shows what happens in the mirror universe when evil Kirk, Scotty, and Uhura come back but Spock has been somewhat transformed by his experience of meeting our universe crew.