We did one at Pottery Barn and Williams Sonoma. Since the two stores are owned by the same company they're linked into one registry making it super easy. And I think there was another store or two that could be linked as well that we didn't use
It really just depends what stores you like things from or where your family largely shops. I'm doing amazon and zola because on zola you can add items from any stores like kohls or BBB, my family shops at kohls alot and I love their food network line of kitchen stuff.
We are registered at Target and Amazon.com. I love both registries, they let you track which gifts have already been purchased, and it's sort of fun knowing friends and family are shopping for the shower, and it'll be exciting to see who bought what! I also love that it allows some of our out of state family and friends the option to have items shipped straight to us - unfortunately not everyone will actually be able to make it to the wedding.
I am using Zola.com. This site, you can ask for traditional gifts and cash. You also have the ability to choose your gifts and delay shipping. Example: If someone got you a gravy boat but you really wanted that cutting board - you can use this site to 'exchange' items so you get exactly what you want. For the delayed shipping, let's say you are on your honeymoon and that one, forgetful, friend purchases you a wedding gift and it gets shipped while you are out of town/country. This item will not ship unless you click the ready to ship button.
We ended up using the "add this to registry" button through MyRegistry.com and then just picked out restaurant websites/art museums/etc. that we added. We also synced up Target and REI. We don't want a ton of stuff, we'd much rather have experiences (like going to the movies, local restaurant gift cards, spa experiences, camping trips, etc.). We also made some "cash funds" too.