Enterprise and Discovery, for me.
I still remember my first time watching Broken Bow, on my family's PC in the dining room, all of us sat around watching it in the dark. We were watching a dodgy copy we'd got off my uncle, a few days after release, as Sky One weren't set to air the show for another 3-4 months. I loved every second of it, right from the start. Never stopped loving that show.
Discovery speaks to my own television tastes more than the other Trek shows. I generally favour shows produced for streaming platforms, mostly because that's where you'll find the majority of the top quality prestige television shows, and I've leant heavily into those for a number of years now. Serialised storytelling, great cinematography, etc. Discovery is just my cup of tea.
Special shout out to DS9, too.
I can enjoy things about all the shows, and like them all. ENT and DIS really stand out, though.