Although Sunset Park's Mister Hotpot has been open around a year, I couldn't find a mention of it here, so I thought I should rectify that.
Not only is Mister Hotpot an excellent hot pot restaurant, they accept credit cards, take reservations, are open late, and have a modern, clean space, with a large enclosed party room in the back. The only downside (for some) might be the booming techno music, but if you read Yelp reviews, apparently a large portion of their customer base enjoys that.
They have three broths (herbal, pork, and spicy), and last night I finally got to visit with a large enough group where we could get all three at once, in two split pots, doubling up on the spicy. All of the broths have good depth of flavor. A separated dish of mix-ins is provided at the beginning of the meal for you to mix your own dipping sauce if you wish, although a tasty, citrusy house sauce is provided as well.
There is a huge variety of quality, fresh ingredients available, including some delicious and highly recommended unusual ones such as fish skin. Last night we also tried wood ear fungus - not my favorite. There are various combo plates available - you can see the beef combo in the photos linked below - this is a good way to go if you have a large group.
They do a lot of social media promotions, so check Yelp, Facebook and so forth to see if there's anything going on when you go. Oftentimes they'll have a free dessert or ingredient for checking in to one of the aforementioned services.