Howl at the Moon has (or will have) dueling pianos. It used to be downtown, near the old Church St. Station, but it closed a couple years ago and is re-opening later this month on I-Drive, near Mercado. The website has an exact date, but I think it was around the 24th.
Speaking of Mercado, Cricketer's Arms is a British pub there, the guy who plays on Fridays (Jeff Howell) is great. Bahama Breeze, just a block up I-Drive, also has live entertainment quite often. Both attract a somewhat older crowd (or mixed-to-older).
As a 30-something, I still recommend you try Citywalk at least once. Pat O'Brian's is a blast, and Margaritaville has some good cover bands after 10 p.m. (not just Buffet tunes, they play rock from the 60s thru 90s). Throw in Bob Marley's and the live street entertainment and there is plenty to do, even if (like me) you feel a little too mature for the Groove. Parking is free after 6 p.m., a ticket to all the clubs will cost you $10 (or each club charges $7 at the door).
Hope this helps.