Depends on what you are going for! If you are going for views, most of the people will recommend Top of the Rocks because you can see the empire state building, central park and most of New York from here.
On the other hand, at Empire State, central park is blocked by Rockefella Center. But if you want to go there for sentimental reasons and to re-create movie scenes like Sleepless in Seattle, Empire State is probably more Iconic!
When to go up? Having been up to most of the world’s tallest buildings like Burj Khalifa in Dubai, Petronas Twin Towers in Malaysia, 101 in Taiwan, Marina Bay Sands in Singapore, Oriental Pearl Tower in Shanghai, stairs at grandma’s place (hey, it’s tough when there’s no lift and I cannot walk!!), I always recommend the evening time. Check the local sunset timing because you get both views, day and night for a single ticket!
At Rockefella Center, there’s the famous Radio City, a cool lego shop, Hercules statue, cool lego shop, the famous big Christmas Tree if you come during Christmas! And did I mention a cool lego shop?
Then just nearby (radio city), St Patrick’s Church is a must go! It’s beautiful beyond words. If you are lucky, maybe some celebrity is getting married in there!
Oh yes, and we got a “discount coupon” for Top of the Rocks from our hotel. It’s call “Mini Cards“. You can print from the website too to save a couple of bucks!