I second the cheese plate, especially one cheese called something like Port Robert. I'm not normally a big cheese fan, but this was incredibly creamy and delicious.
Also, I had the spring tasting menu. Almost everything was very good, but I was particularly impressed by the chilled foie gras (no fancy preparation, just superb foie gras) and the roasted (I think) turbot (and I'm not normally a big fish fan either).
My only disappointment was the dessert tasting plate, which was underwhelming--surprisingly so, since I have a pronounced sweet tooth and the pastry chef at GT is celebrated. Interestingly, I had the same experience at Jean-Georges: an excellent meal followed by a disappointing dessert tasting. I wonder if the need to produce tiny portions cramps a pastry chef's style. (Incidentally, the problem wasn't that I was too full to eat any more.)