Woolery, Marshall, Peck, et al are up on there on the best non-GT host scale, but we've forgotten our newsgroup friend Geoff Edwards(though he was among the considerations for Feud before Dawson got the gig), and Wink Martindale, who I believe with 33 years between the premiere of What's This Song on NBC and the ending of Debt on Lifetime, has the longest hosting career without ever doing anything G-T.
Tom Bergeron among the more recent stable of hosts.