If you want a good PS that will set you up for a good seat for IllumiNations, pretty much your only choice is Rose & Crown at UK. None of the other restaurants have good views of the lagoon, which is where you need to be to see the show.
You also have to be very careful about what time you request, so that you're not sitting and sitting and sitting at the table, since eventually, you will be gently prodded to leave, since there will be other people with PS after you. Also ... making a PS at Rose & Crown doesn't guarantee that you'll get a seat outside, which is obviously where you need to be to see IllumiNations!
That said, Rose & Crown is a good choice, since the food isn't too exotic or unusual -- sausages, chicken, meat pies, etc. All very recognizable, all quite good.
However, if I had only one PS to make at Epcot, my first choice is always the German Biergarten. It's a buffet, there's great entertainment, and there's plenty of beer.

And if you time it right, you'll be walking right out of the Biergarten in time to get a great spot in front of Germany to watch the fireworks!
