I think Riker on the Titan would be the most likely bet. The lead on Trek series in usually the captain or the one in charge and he fits that role.
A Data series would get old in a hurry, given the way they used him in the movies with cheesy catch phrases and gimmicks.
Maybe Worf, he got a lot of development and backstory. But he's too grumpy to carry a show. Star Trek: Tales from the Security Office.
Maybe Geordi, we never knew that much about him. Give him his eye surgery in the pilot to get rid of the VISOR.
Beverly would be ER in Space. And no way for Troi.