No. 5: Jersey Shore

After taking the reality-show world by storm in 2009, the uber-tan, fist-pumping “Jersey Shore” housemates from Seaside Heights signed with MTV for a second season and continued their infiltration of the known universe. Snooki, J-Woww, Pauly D, the Situation, Sammi, Vinnie, and the others lurked in every corner, ringing the bell at the New York Stock Exchange, “Dancing With the Stars” and covering the Grammys.

Not satisfied with dominating television, they branched out into other arenas. Music? Check: The cast took part in an Enrique Iglesias video for a song appearing on the “Jersey Shore Soundtrack.” Fashion? Yep, both the Situation and J-Woww launched clothing lines this year. Oh, and Snooki designed a slipper. Literature? Um … kinda. Order your copy of “Gym, Tanning, Laundry” now. An iPhone app? The requisite item for any self-respecting pop-culture trend is available in both Snooki and the Situation models. Film? Not yet, but we can always hope.

With the U.S. conquered and the cast headed south for the summer to film Season 2 in Miami, MTV set its sights overseas. In March, theĀ  show aired in more than 30 countries, bringing the tao of G.T.L. (or “gimnasio, bronceado, lavanderia” in Spanish-speaking markets) to the rest of the world. To prepare unsuspecting foreign viewers, MTV ran a series of ads called “Get Jersey Shored.” And voila, another proud U.S. export joins the ranks of Jerry Lewis, David Hasselhoff, and “Walker Texas Ranger.”

With exposure like that, a round of spoof videos was inevitable — and we weren’t disappointed. They came in droves: for instance, “Little Jersey Shore,” with scenes from the show re-enacted by juice-box-toting toddlers. Or the actual castmates spoofing “Twilight” on “Jimmy Kimmel Live.” Last but not least, late-night host Craig Ferguson teased us with a trailer for “Jersey Shore: The Movie,” starring Mila Kunis as Snooki.

“Jersey Shore”-themed Halloween costumes topped the most-popular costume list this year. Even celebrities got in on the act, with Joan Rivers going as Snooki and Ellen DeGeneres dressing as Snooki’s pouf. The “Regis and Kelly” team performed a segment as the “Shore” cast (Art Mohr as J-Woww was really something special). And yes, the real-live cast dressed up, too.

Just when we thought they were already as ubiquitous as sand at the beach, the Garden State gang made Barbara Walters’s list of Most Fascinating People of 2010. Mike “The Situation” Sorrentino is now one of the highest-paid reality stars. When his turn on “Dancing With the Stars” ended, ratings dropped quickly, especially in the 18-to-49 demographic. Snooki bounced back from her beachside arrest and is now an author — seriously. Her first book arrives in early 2011, mere months after she announced to Twitter followers that guidette was reading her first book ever. This is all great news for fans of juiceheads, gorillas, and grenades. More good news: The bikini-clad shore dwellers will be back for a third season — and back home in Jersey — this summer.

–Melissa O’Neil