I've been watching an episode a day for several years now. I started with "An Unearthly Child" and as of last night I finished "Full Circle."
The funny thing is, although I didn't plan it this way, I'll end up being on Peter Davison in May, Colin Baker in June, Sylvester McCoy in July and Paul McGann in August, during each one's celebratory anniversary month! I guess that's one advantage to Doctors 6-8 all having such short runs...