Voyager is maybe my least favorite Trek (I still like it a lot!) but it's got my vote for "the most comfortable" because it always feels so low-stakes. Ironically I have probably seen more Voyager than any of the others for that reason.

Voyager and TNG. Best shows for putting me into a good mood.

Also opting in for Voyager. I swear, I can feel my pulse drop as soon as the Intro starts.