For me it's Enchanted Garden, hands down!
I felt like the food at all three MDRs was amazing, and since my kids and I are not picky at all, we were thrilled with the food everywhere.
For me, it boils down to decor and ambiance. I am a HUGE Alice in Wonderland fan and I loved that the menus featured some of Alice's flowers! I also thought it was simply stunning! Day and night. Just a gorgeous restaurant!
Now this isnt to say I didn't love the other two.
Animator's Palate is next in line for me. I felt it was a very elegant restaurant and I was impressed with the details and setting.
Royal Palace honestly did not impress me as much. But it was our first night on our first cruise and I was dealing with allergy/intolerance/chef/server/head server issues and our table was in a crappy location and on and on. It is the restaurant I am most looking forward to on our next cruise as I feel we didn't get to really experience it properly that day.