We just learned "Fun Fun Fun" for a regular audience member. We play once a week on a deck at a marina on a lagoon across from a state park. The location brings out a lot of beach, tropical, and other "summer songs" from the snowbirds who are vacationing down here. And they are fun to play.
The song is Fun Fun Fun but with the two of us, we don't have all the harmonies so I put some of the parts on the synthesizer and included it in my backing track (I make my own backing tracks for my duo)
"Fun Fun Fun" - The Beach Boys