I found out the ending for Lonesome Road. You confront Ulysses in the Divide, and he turns around to talk to you with an engraved 9mm pistol in his jacket. After pulling it out, he says simply "Sorry, but the game was rigged from the start." and shoots you in the head. The last thing the Courier sees is Ulysses' flag, and the canon ending slides play as he walks away into the sunset.