Hope you don't mind if I use your format, TBC
The Next Generation
I was always a fan of Data and Riker. Captain Picard was awesome, but I connected more with Riker than anyone else, and Data just fascinated me.
Deep Space Nine
Sisko was definitely a badass, without a doubt, but I always watched the show for the interactions between Odo and Quark. My favorite out of the group? Mr. Garak.
Never was much into Voyager, but I always liked the EMH.
The Original Series
Definitely McCoy. Kirk was an unabashed kickass God's gift to women and the worst nightmare of his enemies, but McCoy had that southern drawl, that curmudgeonly scowl and that care in his eye that you knew he was going to do his best to save your life.
Phlox. Definitely Phlox. As much as I like Scott Bakula, I feel they could have replaced his role with a broom handle and a pair of those jokey nose glasses, and no one would have noticed.