* "Prometheus" takes the No. 2 spot for second week
* Sandler's "That's My Boy" fails to win many laughs
* Cruise doesn't rock box offices in "Rock of Ages"
LOS ANGELES, June 17 (Reuters) - The animals of "Madagascar 3: Europe's Most Wanted" held the top spot on U.S. and Canadian box office charts for a second straight weekend with $35.5 million, beating new films from Tom Cruise and Adam Sandler, according to studio estimates on Sunday.
The third "Madagascar" movie about the misadventures of escaped zoo animals lifted the animated family film above new release "Rock of Ages," a 1980s-era musical starring Cruise that was No. 3, and comedy "That's My Boy," which landed with a thud at No. 5 in what box office watchers said was the worst opening for a live-action Sandler movie since 1996's "Happy Gilmore."
In "Madagascar 3," the animals - voiced by Ben Stiller, Chris Rock, Jada Pinkett Smith and others - run into trouble after joining a European traveling circus. The movie, produced by Dreamworks Animation, has pulled in $120.5 million in domestic theaters since its release a week ago.
Director Ridley Scott's sci-fi thriller "Prometheus," the story of explorers who discover a clue to the origins of mankind, pulled in $20.2 million to finish second. Its total ticket sales after two weeks is now roughly $89 million.
"That's My Boy," an R-rated comedy pairing Sandler with fellow "Saturday Night Live" alum Andy Samberg, who plays the son of Sandler's deadbeat dad character, failed to excite fans and had a take of $13 million. It cost about $65 million to make, a source familiar with the production said, and was released by Columbia Pictures.
Paul Dergarabedian, president of the box office division of Hollywood.com, said the film's R rating, which restricts it to audiences 17 years of age and older, was likely a key factor in the film's poor performance in its debut weekend.
"Even though Sandler keeps getting older, his key constituency is still in the sweet spot of the PG-13 rating and remain his key demographic," Dergarabedian said.
In 1996, Sandler's golf movie "Happy Gilmore" turned in roughly $8.5 million in its debut and went on to make only $38.8 million in domestic theaters, according to Boxofficemojo.com.
SLOW START FOR "ROCK OF AGES"
Broadway musical adaptation "Rock of Ages" finished in third place with $15.1 million for its story of a young couple, played by Julianne Hough and Diego Boneta, who pursue their dreams of stardom. Cruise plays an aging rocker and Alec Baldwin, Russell Brand, Bryan Cranston and Catherine Zeta-Jones also star.
"I thought it would do a little bit better this weekend," Dan Fellman, president of theatrical distribution for Warner Bros, told Reuters, adding the strong ensemble cast should lure audiences for several weeks to come. "It didn't jump out of the box but I think we'll catch up slowly."
Warner Bros. unit New Line Cinema produced the movie for about $75 million, and Fellman said he hoped that "word of mouth" would help the film grow with the coveted younger male audience in the next few weeks.
"The film plays older. It will take a little bit of time to catch the younger male audience, but while the music of the film is not their generation, it's certainly become classic and they listen to it," Fellman said.
"Snow White and the Huntsman," a dark, action-filled take on the classic fairy tale starring Charlize Theron and Kristen Stewart, earned $13.8 million over the weekend, taking fourth place in the chart. Its total domestic sales hit $122.6 million after three weekends in theaters. Viacom Inc's Paramount Pictures distributed "Madagascar 3," which was produced by Dreamworks Animation . Time Warner Inc's Warner Bros. released "Rock of Ages," and Sony Corp's movie studio Columbia Pictures distributed "That's My Boy."
"Prometheus" was released by 20th Century Fox, a unit of News Corp. Universal Studios, owned by Comcast Corp , distributed "Snow White and the Huntsman."