He's SO my favourite incarnation!
They do say that when a part has been played by more than one actor (e.g. Doctor Who, James Bond, Holly from Red Dwarf... etc) that your personal favourite will always be the first one that you clearly remember seeing.
I was born in November 1980, so was only 3 when the Peter Davison/Colin Baker handover occurred, therefore can't remember anything pre-Colin Baker. I remember Sylvester McCoy more clearly, but Colin's my fave.
I get the impression that Colin's generally the least popular - e.g. if you wrote the original seven Doctor actors' names onto seven doors, and asked DW fans to go into the room that corresponds to their personal favourite Doctor, Colin's room would probably have the least number of people in it.
But Colin will always be THE Doctor for me!