I would not do GF Cafe. It is ok, but basically is the coffee shop at GF, nothing special. I loved LTT, but that was when they had characters. Food is good, but the character experience was the best in MK. We liked the atmosphere and decor here. Food is plentiful and good if you like their choices (turkey, mac and cheese, beef? and good cobbler)
The Wave was also good. We liked the food, but didn't love the decor/atmosphere. The room was big and not really cozy. I guess I though it would be more elegant, being the "nice" restaurant in a Delux resort.
So, I guess if it were me I would pick LTT if I were in MK for the day. If I wanted to dress up a bit and take longer for a nice dinner, I would pick The Wave.