Check out Marriott.com and use the Corporate Code MMF - that's Marriott's Friends & Family code. I've never paid more than $140/night for the Fairfield Inn on Harbor - and it's SO CLOSE (you can see Space Mountain, the monorail ... and even fireworks!) from the hotel, so it basically feels like an on-site hotel to me. There's also a Panera and McDonald's in the parking lot on the short walk from the hotel to the park, so it's a great way to grab a filling (and cheaper!) breakfast on your way into the parks.