I think there's a hotel directly above the Beacon Theater. A bit pricey, but you can't beat it for convenience. There's a subway stop on Broadway, maybe a block or two from the theater, so you could really stay anywhere in the city and be a quick train ride away.
Parking anywhere around there sucks. If you can find a spot on the street, you're all set. If you park in a garage nearby, be prepared to spend $30-40 for overnight parking.
I love The Beacon.