We have ours through Zola and really like it so far!
Zola is partnered with a variety of brands that you can search through on their site. You can also make big ticket items a 'group gift' so that your guests can contribute whatever amount they want to it, or they can buy it outright. If the brand or gift you want isn't on Zola's site, you can add it from another site. You also have the option of linking registries from other stores to your Zola registry. (we're registered with them, target, and crate&barrel). They also have cash fund listings, so you can have a listing for a Honeymoon Fund, New Home Fund, or a Charity Fund!
We did Crate & Barrel, Target, and Bed Bath & Beyond. BBB was a popular one because they pretty much always have some sort of coupon offer happening.
I'm not sure if Zola has changed, but I've heard about guests getting spammed from Zola to buy registry gifts, so we didn't use it. Guests that wanted to give money either sent it through the mail or put it in our card box at the wedding.
Amazon! It was amazing, plus you can add your address, so when guests purchase something off your registry they have the option to ship it right to you! It was a nice surprise to get things in the mail
Most guests will purchase tangible gifts. If you don't have a registry or if you register for cash/experiences, many people will buy you a tangible gift anyway that you may not want and can't return, because the alternative is not a thing in their social circles.
Target and Bed Bath and Beyond are the most popular with the widest variety of items to choose from and you aren't restricted to appliances and linens only. Register for games and things related to shared hobbies/interests. You can list the registry on your Withjoy/wix.com site and they just type in your names on the store site to access your wish list. Easy and simple.