I wouldn't call myself a fan, because fan by definition is a shortened version of fanatic, but when I worked at the video store during college I unearthed 2 giant boxes of Dr. Who video tapes in a back room, and my boss let me take them home for a few weeks, seeing as he forgot he had them in the first place. I had no idea where to start, so I just jumped in sampling a little bit from each Doctor. Tom Baker won out and was my favorite, and I watched a bunch of his stuff, and found his whimsical take on the Dr. to be enthralling.
On Saturday my brother mentioned he was interested in checking out the new series of Doctor Who, since it started on BBC America that evening. This took me by complete surprise, because I can't get my brother to watch most anything SCIFI. I practically had to drag him kicking and screaming to Serentiy, which he LOVED, and now he LOVES Firefly. So, I was game if he was. Luckily BBC America ran the Ultimate Guide to Dr. Who before hand, it gave him a really well packaged introduction into the world, the characters and the mythos behind the Dr. We both loved the first episode and Matt Smith in particular. He's very charismatic and he exudes an old soul, which has already been mentioned as important.
As Collen pointed out, Karen Gillan's Amy Pond is really hot. Just another reason for me to be excited about the show.
This will be the first time I've put an effort into watching Dr. Who weekly, so it should be interesting.