any good brunch places in nassau ?

I would recommend The Garden City Hotel.

I also like the Palm Court at the Carltun - I will say that I have eaten here a number of times (my grandparents like to go there for brunch so we go there as a family from time to time) and it is good - but 3-5 times the service leaves a lot to be desired. Last time we went I had a little over 3 hours until I had to leave to go to the airport to come back to NY. We sat at 12pm. The service was so slow that after 2 and 1/2 hours when we finally got our entrees (they forgot to put mine in so I had to wait and didn't get it until the rest of the table were done eating) it took another 45 mins to get the check and it only came as dessert was brought to the table. Needless to say that was the worst experience usually the service is good not quite where it should be.