Kosher at Six Flags Great Adventure
I'm so glad this question came up. because i ran the kosher food at six flags for almost three years. before they had the season long stand, Reuben's Glatt Spot, was in charge of the pesach food, and they were the kosher caterers of Six Flags. i spent 3 pesachs doing six flags, and about 10 days out of every summer for 3 years. Reuben's is no longer located in Elizabeth, he has relocated to West Orange, but he is still under the supervision of Rav Teitz. rav teitz also gave the supervision on the six flags location. Rav teitz adheres to the strictest levels of kashrus, and he doesn't compromise it anywhere.
There's a Reuben's Glatt Spot in Elizabeth under Rabbi Teitz' supervision; if this is the same establishment, I'd imagine it's ok, although curiously enough there is no mention of it on their website, so I'd check it out carefully if I was you!