Doctor Who

Try YouTube.

The classic Dr. Whos (Doctors' one through eight) are mostly available on Youtube. There are several episodes of the first few seasons that have been lost forever. The new Doctors' you can get pretty cheaply except for the last season.

By the way, there are over 450 hours to watch... there are many great Dr. Who episodes. There are others that are not worth watching. I would pick and choose rather than watch from beginning to end. The internet will tell you which series are good watching.

Here's a good resource for all info on Dr. Who episodes, including rating...I believe there are links where you can figure out where to buy them, too.
http://www.imdb.com/title/tt0436992/eprate

The list of missing episodes

http://en.wikipedia.org/wiki/Doctor_Who_missing_episodes

I first started watching very young the last story of the second doctor http://en.wikipedia.org/wiki/The_War_Games

I have long wanted to watch it again - bizarrely in the early 2000s the ABC in OZ started broadcasting all the episodes from the very first series in chronological order at 5.30 on week day afternoons and I caught up will all I'd missed - hoping to see the 10 War Games again after 30+ years.

They didn't show it. Some sort of legal hassle with the writer/producer? Can't find any reference to it now. Must be sorted because it's been on DVD since 2009.