The long version of Beach Baby by First Class.

Island In The Sun by Weezer.

Lil Rob - Summer Nights

Ok so this is slightly in jest, but honestly..I wouldn't mind listening to this with a corona or something.

Wow, I can't believe nobody's mentioned Bob Marley yet- "Three Little Birds" or "Jammin'" would be good.

Another kinda obvious one- The Beach Boys. I'd say either "Good Vibrations," "Sloop John B," or "Wouldn't It Be Nice."

Also, "When The Sun Goes Down" by Kenny Chesney- he has a live version with Uncle Cracker that's cool.

I forgot this one! Summertime by the Sundays. :) Love, love, love this song!

Before Mark Wahlberg was an actor, and when he had a funky bunch: http://www.youtube.com/watch?v=-eSN8Cwit_s

Also, pretty much any Katy Perry song.