Originally Posted by
AnnirasSweets
Well, they're all useful to earn gems from recipe mastery but outside of the basic appliances, most only have three recipes on them; the ones that have more recipes will also have most of those extra recipes indefinitely locked by past goals. And again, other than the basic appliances, most others only offer recipes that yield between 3-6 coins per serving so if you're looking to earn coins faster, the basics are the way to go. There is one appliance that gives double gems for recipe mastery but it costs gems to purchase so that's a bit of a wash as well.
If you look in my signature, you'll see a link to the Recipe Guide thread. There, you'll find the details for every appliance ever released in the game including what level they unlock at, what parts they require, what recipes they have, how much the recipes earn, everything you could want to know. Also, the charts are color coded so you'll know which recipes are open and which ones remain goal locked after purchase. There's also images of every recipe in the game so if you're looking for recipes with a certain look you'll know right away which appliance is going to work best for you.