I actually disliked him a lot in The Christmas Invasion, mainly for his treatment of Harriet Jones. New Earth I was indifferent about; in Tooth and Claw I found him and Rose and their giggling extremely unlikeable again. School Reunion won me over a bit - it's a great episode, even moreso in retrospect - and then there was The Girl in the Fireplace, and suddenly he actually was the Doctor for me. I think I needed to see him without Rose to actually get there - their dynamic was so offputting for me. So yeah, I'm with you on liking Ten much more from s3 on!