As a Samsung fan, kinda hard to find a team to support now. The new Samsung roster seems they could be interesting, but far too new to tell at this stage. The KR scene as a whole feels a little lacking compared to normal (as expected with all the transfers), so probably wait a few more weeks before I find a team I really want to support there. Only thing that really airs Australia time anyway, so end up watching OGN/LCK mostly.
For NA LCS, I'd have to say C9 probably, followed by underdog Team 8. C9 always seem to do well without changing their roster/resorting to imports, and it's what I liked a lot about the old M5 too.
EU LCS, ehhhhh. Likely Gambit if I had to pick one, but that's purely because of being my original team when I first started watching competitive, not so much their recent performance. My interest in EU LCS hasn't really been there since S3 sadly.