TL;DR: Go with Amazon, you cant go wrong. I once had a total disaster where my Texas cousins bought three of the same blender because our niche app glitched out. Be careful with those smaller sites! I would suggest sticking to a major retailer. Just set up any group list from Amazon. Make sure to toggle the setting that hides purchased items so the surprise isnt ruined.

Checking in a day late but I spent a good chunk of time testing these for my own family last year because we have people in three different time zones and zero patience for tech issues. If you want something reliable that wont confuse your parents, MyRegistry is probably your best bet. Its a very stable platform that acts as a universal hub. It works. Here are a few technical reasons why it works for this specific scenario:

• Universal button: You can add items from any store on the web. People arent locked into one retailer.
• Syncing: If someone already has a list at Target or Macys, you can sync those existing registries directly into the main family account. It saves a lot of manual data entry.
• Clear status tracking: The Mark as Purchased feature is prominent. It asks for a store name which helps prevent those Texas vs Chicago double-buys you're worried about. Another decent alternative is Wishlist.com. Its got a much cleaner, more modern UI than Giftster. It feels more like a social feed of gift ideas.
• It handles group privacy well.
• You can set it so the list owner doesnt see what has been bought. Keeps the surprise alive.
• No app download is strictly required as the mobile site is responsive enough for non-techy users. Stick to these two if you want to avoid the clutter of Secret Santa sites. Theyre built for registries, not draws. Just make sure everyone knows how to hit the bought button or the whole system falls apart...

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