Sorry if this has been said before, but my favorite of the custom worlds is definitely Mayfield Springs.. it's just so perfect and really detailled.
From the Store worlds I'd probably say my top 3 are Hidden Springs, Lucky Palms and Sunlit Tides (although if you have IP and Isla Paradiso it's not really "needed" anymore but it's still beautiful, plus it's not as much of a laggy mess as Isla Paradiso) :)
And idk if you're asking about EP worlds too, but from the EP worlds the must haves in my opinion are Bridgeport and Appaloosa Plains :smiley: