I’m gonna go ahead and say the Dollars Trilogy all take place in the same setting, following Clint’s character as he keeps changing aliases. I only say this because I’ve run into folks who claim they are only thematically related and that Joe, Manco, and Blondie are in fact different people (despite, you know, wearing the same outfit, but I guess there aren’t a wide variety of clothing retail stores around the Frontera.
Anime-wise, there is some absurd number of animes that all take place in the same multi-verse as Tenchi Muyo. Some shows (Such as Tenchi GXP) explicitly share the same direct continuity with the OAV series, others are basically alternate universes (such as Tenchi Universe, Tenchi in Tokyo, Magical Girl Pretty Sammy, etc.) and others seem to be a few more universes removed but are supposedly still part of canon (Dual! Parallel Trouble Adventure).
It doesn’t help that the Tenchi franchise is thick with alternate universes in-canon (such premise was the source of a hysterical two-part episode of Tenchi Universe where they kept hopping universes, changing the premise and genre of the show every five minutes or so)