I once shot a Contender in .35 Remington, loaded with a cast 250gr. bullet, supposedly 2 grains heavier than recommended powder charge.
It kicked so hard I didn't believe it, and had to shoot it again.
That, and another Contender in .357 Maximum ruined it for me. I wouldn't own a Contender on a bet. I revile them.
As far as long guns go, the most memorable was a Weatherby in .378, with a brake. It seemed like a 12 gauge slug gun to me, tolerable, but not enjoyable. I once had a 600 Remington in .308 that wasn't fun, either. I don't like recoil any more, I can only take about 12 rounds of .454 and I get headaches and flinch pretty bad.
Now I shoot stuff like .17 and .22 Hornets and call it good. Shooting is fun again!
You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.