My favorite character is Kirk. Sometimes I like the other characters better, but he really is just the best. Kirk wins the day because he is pure awesome.
My all-time favorite character is Spock. I like him the best because he is neither at home on Vulcan or Earth. His home is the ENTERPRISE. His logic and intelligence are an important part of his Vulcan half but his flawed feeling human side is just as important.
I love Picard assurance, bravery, determination and all the qualities that make a great exploration captain.
I relish the shrewdness, constant plotting, raw emotions and thirst for accomplishment of Garak ; I understand some people might not like him as I used not to as well but he grew on me, a lot.
IMHO those 2 characters are separated from the rest at the top.
My favorite has been and always will be Spock. Through Star Trek: TOS, Star Trek movies, and Star Trek books, Spock has always been the most--ranged--character. I have no idea how to say it, his character is just the one that was the most well crafted, versatile, new, diverse.....etc.
So, top 3 spots:
1. Spock
2. Picard/Data
3. Mark Lenard/Q