The first Tenchi TV series. This is not related to the OVA series but is instead a re-telling of the story with the same characters (with some additions and changes to them). I actually prefer this over the OVA, but I saw this before seeing the OVA.
A second Tenchi TV series that has nothing to do with either the OVAs or the first TV series. Art style doesn't seem as good and the story is somewhat boring. It picks up at the end, but not enough to save the series.