After a good long, thorough search, I've discovered that this site has no Tenchi thread, so I figured why not make one? This place is looong overdue for one.
Tenchi is an amazingly epic anime. It played on Cartoon Network's Toonami in 2000(that's right, the old Toonami with DBZ and Yu Yu Hakusho). That's when I first liked it as well. It was originally made as an anime, but as many series. Tenchi Muyo was th first. It was 12 episodes, and is noted as an OVA/OAV. Then there's Tenchi Universe, and 26 episode series. And then Tenchi in Tokyo, the 3rd spin-off which is also 26 episodes. In each series, the characters are different in background stories, and how they meet, but their personalities stay the same.
In 2005, the 'continuation' of the first OVA was made into a six episode series, with almost all the voice actors and actresses reclaiming their original roles. All except for Petrea Burchard, who originally played the 2nd main character Ryoko, and Bob Papenbrook who played Tenchi's father(Nobuyuki) and grandfather(Katsuhito). It's not known why Burchard gave her role to Mona Marshall, but Papenbrook could not continue because he died of chronic lung complications at the age of 50 .
There are also other spin-offs that are unrelated to the original series. These would be the Pretty Sammy series, starring Tenchi's Sasami Masaki Jurai. Other characters like Ryo-oh-ki(who is made into a male for these series), Mihoshi and Washu reappear for these.
There are 3 movies, all of which are presumed to have branched off of the Universe series, because the character Kiyone appears in the movies as well as Tenchi Universe and Tench in Tokyo, while she doesn't in the OVAs.
Tenchi Muyo! (all series) on Wikipedia
Tenchi Muyo! Ryo-Ohki on Wikipedia
Tenchi Universe on Wikipedia
Tenchi in Tokyo on Wikipedia
Now, to sit back and watch thread die.