If you plan a trip to Connecticut and wondering about Mohegan Sun or Foxwoods, I can tell you the nightlife is much better at Mohegan, though when it comes down to gambling it's pretty much a split down the middle. Price wise, Mohegan is pricier and will probably run you $300+ on a weekend. If price is what your concern, then stay at Foxwood (either the Towers or Two Trees hotels).
I much prefer Mohegan for gambling because of its Vegas-style vibe but Foxwood is on a city bus route to New London with train service to New York and Boston so, Foxwood is better connected.
I’ve been to Mohegan Sun plenty of times, but never stepped foot in Foxwoods, though I have seen pictures of it and my impression of Foxwoods is that it looks like a 1980's mall with sections which don’t aesthetically match.