I own all 4 of these diffusers and I love all of them but I do have my favorites.
#1 Favorite: Aroma Lite (I love that it goes for 8 hours.)
#2 Favorite: Petal (Only goes up to 4 hours, but I still love everything about it. Especially the price.)
#3 Favorite: Lotus. I have the old one, not the new one.
#4 Favorite: Aroma Ace (Love but can't use in bedroom. Too noisy. And DO NOT use fractionated coconut oil in this one. Oils only.)