Things that make girls giggly and excited:
boys, romantic comedies, zack morris, MASH, flowers, boys, cupcakes, butterflies, sunsets, beaches, love notes, markers that smell like fruit, babies, popsicles, boys, soft blankets, sleepovers, soda, ice cream, truth or dare, hallmark commercials, hearts, justin beiber, puppies, boys, kittens, things that are pink, boys doing heroic things (like saving puppies or things that are pink), things that have polka dots, NKOTBSB, any kind of baby animal, secrets, my little pony, phrases like squish! squee! and OMG.
Things that make boys giggly and excited: farts. beer. boy scouts.
Especially reminiscing with long-time buddies over a box of Boy Scout memorabilia that one's mom (who shall remain nameless, but her name rhymes with Schmother Scmin-law) recently off-loaded on him.
And maybe sometimes Justin Beiber.