To me, dress-down, no money limit, and buzzy just don't go that much together. The real problem may be that you don't know exactly when you'll be back in Manhattan, and it's likely to be after 8, when things are busiest. You might be able to get a reservation for 9pm if you want to commit to eating then. I have no experience here, so I"m not sure about the timing, but it seems that these games never finish before 7:30. Sunday isn't always the busiest night of the week for dining, but with the season in high gear, I think you should be prepared for crowds, as always seems to be the case after Thanksgiving. So reservations are a must.

I think you'll be too underdressed to feel comfortable at NoMad.

There's probably no way you'll get a reservation at Minetta Tavern, but if you can, it does have the best burger of all these recommendations.

Gramercy Tavern's Tavern room doesn't take reservations, is both fairly casual but really good, and might not be too hard to get into on a Sunday, so I think that's an option. They serve no burger or steak, though there's a good kielbasa.

Little Owl is nice. That's a good choice.

The Spotted Pig (also no reservations) might be exactly what you're looking for but can have a bit wait,m especially after 8.

Or you could just go to Five Napkin Burger at Union Square if you just want a cheeseburger. They've got a good one, but you should probably make a reservation.

Finally, there's Artisanal. It's got a great menu, including steak frites (and a burger). It's not exactly in the area where you were looking, but it's convenient to Penn Station.