Found this in my living room this morning, very much alive. It was a nice day yesterday, and apparently someone left a window open.
This is a female Eastern Hercules Beetle (Dynastes tityus). The males have pretty impressive horns out front. The grubs of these beetles feed on dead cherry trees and black locust, and I have a few dead black locust in the back.
For the record, this is the largest beetle found in the U.S.