BLT Prime or Peter Luger?
BLT Prime and Peter Luger's are two completely different restaurants. BLT Prime is great - a more modern atmosphere and a great menu. Peter Luger is classic, the steak is great, smothered in butter which always makes it better, they have a menu, but traditionally at Peter Luger's you order a porterhouse. I would say, just try both!
Have not eaten at BLT Prime but we ate at Peter Luger last weekend and I thought the porter house was amazing. As many steak places in New York, they slice the steak in advance. Generally we curse this strategy as the juices leak out and the steak cools too fast. In this case the steak was so big it stayed warm enough. They also tip the plate to catch the juice. I loved it. I also recommend the creamed spinach.