Ruger Blackhawk 357 Maximum... talk about an ear splitter. I took it out, shot it, and traded it right back off at the shop I'd bought it from. That thing hurt with ear plugs in. I do regret not hanging onto it longer given what they sell for these days, though.

308 Norma Magnum. It was a itty bitty thing that kicked like a mule, and I wasn't shooting over maybe 100yds tops at the time. I didn't keep that one very long, either.