At the parks, I love the fiesta at Mexico in Epcot - FWIW not the cantania outside but the stand by the jewlry maker.
At the resorts, I my favorite all time margherita was the ones at the beach club pool bar - It was AWESOME and followed closely by the one at the dolphin pool bar.
Unfortunately I haven't tried one at CSR so I look forward to hearing your report LOL
TJ