For the counter service we usually hit Cosmic Ray's twice in one visit...I really miss being able to get breakfast here. We also hit Sunshine Seasons at Epcot usually twice...once for a meal and once for a snack. I also try to get to Yorkshire twice.
For the sit downs...we used to go to Le Cellier twice, but the last two times were so rushed, food was alright but not what it used to be so this trip we aren't even going once. Depending on the length of our trips it varies...if we are only there for a week we don't hit the same place twice for the same meal (breakfast/lunch/dinner). But if we are there for 10-14 days we will hit Kona twice for sure, others it really just varies.