I've gotta agree with Capt. Riker here, I don't think he could carry a whole book himself, but I would love to see him become a regular character in one of the current series. Do we know yet what happens to him after Voyager gets home?
When we first heard about the Titan series, I thought it was an opportunity to make Barclay a regular as Chief Engineer aboard that vessel, in part because his patient/friendship with Troi seems to be his most significant relationship outside of cats and holodeck characters (didn't know that Melora Pazlar would be on the crew at this point - funny, Barclay's great unrequited love and his only known requited love on the same vessel). Not that I have anything against Ra-Havreii, mind you, who has become quite the interesting character as of
Sword of Damocles. I seem to remember being told that Barclay was now considered a VOY character... though, thus far, the VOY-R books have done fuckall with him; and, of course, possibly the most underused VOY regular in the VOY-R, Tuvok, also wound up on the Titan.
Fictitiously yours, Trent Roman