Sorry for the belated reaction! I'm glad you liked Christopher Eccleston's 9th doctor, and I believe you'd like the entire first season of the new Dr. Who series. As for the Number 10, Tennant's Doctor is a bit weirder than Eccleston's, but there are a few episodes without Jack Harkness that are really worth watching, too: The Girl in the fireplace (Season 2) and the double episode Human Nature & The Family of Blood and my personal favourite Blink (all Season 3).