We decided on solid core doors for our interior doors in the hopes that they would block out noise. Here I am putting in the first door in Dondon's bedroom. Naturally it turned out to be the one that doesn't hang straight.

The unfinished door:

Now with the rubbed on polyurethane (rubbed on because the brush on left lots of drips and bubbles (this happens to be the kitchen bath)). Once finished the doors look a lot better. It would have been great to get them prefinished, but that wasn't an option at any price.