Lorne Greene

After leaving his home dimension Pylea, Lorne Greene -- aka Krevlornswath of the Deathwok Clan -- starred on the series Battlestar Galactica, then finally settled in as the owner and host of the Caritas bar in the Joss Whedon show Angel.
He is also famous for being the original creator of Star Trek, although the show progressed rapidly from his original concept of "Bonanza to the stars."