Decided to go with someone who was famous before bein' on the show, not after...
I had such a hard time with that one. I didn't know if I should stay away from Barclay just because he was on so often but looking back I guess that doesn't really matter, he still wasn't a main character... But Babylon 5 started during TNG's run so I went with it.
Just about halfway through the entry period! Any more?