I get Catahoula ALL the time for both of mine, I think it's the most common guess. After that people think Cattle dog which I'm always confused by because usually the people that guess that have or know ACD's and can't tell that Cattle dogs aren't merle.
Other than that some of the repeats have been Greyhounds, whippets, JRT's, coyote and a lot of confused looks.
No one ever has argued with me really, I know people think I just made up the breed often but they don't push it. Honestly, usually people just pretend they know what I'm talking about and go "Oh, yeah."
OH! But I did have someone ask once if Traveler was a smooth BC at a trial and one person ask me if they were Kelpie mixes.