yea apparently there is a manga comic series that follows the original OAV
Tenchi GXP follows the OAV but its a bit too over the top.
Tenchi Universe was alright but cuz i saw the OAV i wasn't impressed.
Tenchi in Tokyo - didn't like the story much and i am not sure about the new character and probs.
The movies sound like they follow the OAV but not sure
I should check
www.animeondvd.com to see if it does.