We had a giant sized airline crate like the one LLJohnson10 linked to for our first big pup. He was ~190lbs as an adult. We took the door off when he was ready to have full roam of the house, but left the crate next to our bed. He slept in it with his head and paws hanging out the door at least half the time - the rest of the time he'd be sprawled out on the floor at the end of the bed. He loved his crate.
We started Denna in that same crate - made it smaller by filling half of it with a pillow from our bed. She technically had room to subdivide (b-room at front, sleeping quarters in back) but she never did. She only had one accident in the crate, and that was my fault for leaving her too long, too soon.
Since she outgrew that crate before we could let her have run of the house (due to the tendency to destroy items, not due to any accident issues), we invested in a wire "condo" for her - the 54" wire crate. It takes up a good portion of our living room - it wouldn't fit in the bedroom at all. She only went in there when we left the house. We leave the door closed when we're home, just because there's no space for the door to be open in... she still will go into the crate, no problem, since that's where she gets the BEST treats (major stuffed kong and/or busy buddy toys).
Now that Denna is trustworthy with full run of the house, and hasn't destroyed anything in months, we could probably get rid of the crate all together. But, it did come in handy when we had guests for dinner the other day and she wouldn't calm down. Instead of banishing her to the bedroom, we put her in the crate, where she just curled up and finally relaxed.