ooh I just went to the four treys last night on damen and they had karaoke! It was fun!
I work at Trader Todd's, a karaoke bar. We have karaoke every night starting at 8:30. Mondays everything is half off (everything, food and booze), and I can probably hook you up with the KJ and let you skip the line if you tell me you're from the chainlink.
Sidekicks on Montrose is also pretty fun. I believe they have karaoke every night. Late on Fridays and Saturdays gets pretty crowded, but I've always had a good time there.
I like Piece on Thursday evenings; great beer brewed onsite and really good pizza. Karaoke starts at 10 PM. I might be up for trying the Hidden Cove. I like that it's on the north side. Some of the reviews discussing the foul odors there are a little disconcerting, but nobody's perfect.