All of the pans I have are Wilton Decorator Prefered. Some of the them stack/nest together, some don't. I paid attention lately and my cakes baked with the stackable pans have the dreaded, ugly bulge in the middle, despite the icing dam and settling. I know it's got to be due to the shape of the side of the pan not being perfectly straight. If the pans don't nest, the cake is beautiful.
Any suggestions to best overcome this - other than trash them and buy another brand of pans? I'm only a hobby baker, but have bought up nearly every size of at least round and square. I'd really rather not it all be for waste.

Wilton at it's best is a designed primarily for the homemaker/hobbyist. While there's nothing wrong with that, you do have to understand the limitations of such products. Once you reach a certain level of skill and expectation of how a professional cake should look, you just have higher standards. And you need better pans.

Magic Line will not disappoint.

This happend to me the first time i baked a cake. I just took a long serated knife and trimmied i round. After that I made sure my pans had straigt edges. It's a pain but if you don't want to trash them, this is what you'll have to do.

Their 9 inch rounds are the worst. I purchased Magic Line 9 inch rounds recently at Sur la Table for less than nine dollars each. I can compensate for the other rounds, but not for the 9 inch ones. They're too far off.

Take a look at their square pans, too. Wilton squares have rounded corners.

Wilton squares are the worst!!!

I traded my Wiltons for magic line. Love them!!! I want their rounds now too!

Thanks y'all. I agree that the 9" round is the worst! I have an 8" square just frozen for a cake this weekend. I think I will just try trimming it. In the meantime, I'll look into finding some Magic Line pans.