You can download Real Ghostbusters & Extreme Ghostbusters at:
http://forums.ghostbusters....
If some of the links do not work, you can go to pages 23 & 24 of the forum for newer and updated links.

You can also download all the Real Ghostbusters episodes from all seasons with the following torrent:
http://www.mininova.org/tor...

You can also download Extreme Ghostbusters episodes individually from:
http://forums.ghostbusters....
The episodes are not all on the first page like the first link, you have browse through the forum to download them.

Chances are if you are downloading for the first time, the episodes may not play properly. You need to download an appropriate codec or can try VLC player from:
http://www.videolan.org/vlc/

As a final option you can download the videos from youtube by typing the URl of each individual video into the following site:
http://keepvid.com/