My top 3 without a doubt:
1. Christopher Eccleston
2. Tom Baker
3. Jon Pertwee
Tennant: too hyper, talks too fast, couldn't understand him 1/3 of the time.
Troughton: Seemed too unsure of himself for a timelord.
Smith: Too bombastic? Still think he's odd looking.
Davidson: Indifferent to him. Compared to Pertwee, a bit of a wuss.
Colin Baker: Annoying
McGann: YES! Liked his voice. He'd be #4 on my list.
Sylvester McCoy: I liked how he had some mystery to his character which they unfortunately never fully explored.
Hartnell: No, back to the drawing board.