I used to work @ a department store (housewares & linens). Let me warn you about wedding registries: the registry gals will want you to register for EVERYTHING. They'll give you & your fiance the little barcode gun & encourage you to (mentally) go thru every room in your house & register for Every. Single. Thing you could possibly want. It's incredibly easy to get caught up in the whole process and suddenly find yourself registered for a whole whack of stuff you don't even need, just to have a certain number of items/price point ($25-50, $75-$100, $150+). So take a deep breath and don't let them push you around ;)
Other posters have mentioned registering for high quality, buy-it-for-life items, and that's a great idea. But also keep in mind: what do you have room for? Yes, KitchenAid stand mixers are beautiful, and come in almost every colout you'd ever dream of, but they take up A LOT of room. Ditto for 14-cup food processors. And they're pretty expensive(don't know what they cost you in the USA, but the fancy ones in Canada are $500+). Would a hand mixer be a better idea @ this point in your life? (yes KitchenAid also has fancy hand mixer!) High quality sheets & towels are lovely to use, but again, take up lots of room; you don't need 3 whole sets of bath towels (face cloth, hand towel, bath towel, bath sheet, bath mat OMG), you only need one.
Do a bit of research to find out which store has the best return policy. Can you return gifts purchased for cash? Exchange only? Gift cards? Can you return an item without a receipt(or gift receipt)?If a relative in another city buys you something long-distance, do you have to go to the store across town to pick up your gift, or any store?
Some food for thought. Congrats on the upcoming Mustachian nuptials!