I can haz Doctor Who!

So.  I just found a site that appears to have every Doctor Who episode still in existence available to watch for free.  (It's probably ad-supported, but since I use Adblock Plus, I wouldn't know.  I'd feel guilty about using their bandwidth and servers without giving them any recompense, except, oh, wait, popups are annoying and incredibly easy to use as virus vectors.)

So.  I have Doctor Who.  I have a list of all Doctor Who serials.  I've seen enough to know some are really great, and some are really awful.  Recs?  Where should I start?