As bluegill anglers, we often are fortunate enough to tangle with some other interesting sunfish species. One that I most often hear mis-identified is Green Sunfish. Mostly, I hear folks calling them Rock Bass. Warmouth look even more like Rock Bass, but there are differences, especially in that Rock Bass are often found in rocky streams or lakes, and Warmouth seem to have a preference for weedy slackwaters & ponds.
Anyway, here's some pictures of these 3 sunfish species that might help others with identifying what they are catching: