Originally Posted by PTravel

AOL and Moviefone have a feature that lets you search by rating. Here's the first page of each of a search for "G" and "PG":

Arctic Tale (2007, G)
Babe (1995, G)
Ghosts of the Abyss (2003, G)
Gone With The Wind (1989, G)
Meet the Robinsons (2007, G)
Mr. Bean's Holiday (2007, G)
Mr. Bean's Holiday: with Open Captions (2007, G)
Muppet Treasure Island (1996, G)
Muppets From Space (1999, G)
New York Stories. (1998, G)
Ratatouille (2007, G)
Ruggles of Red Gap (2002, G)
Sandlot, The (1994, G)
Santa vs. The Snowman in IMAX 3D (2002, G)
Spellbound (2002) (2003, G)
Ten Commandments (1956), The (1956, G)

11th Hour, The (2007, PG)
Amazing Grace (2007) (2007, PG)
Are We Done Yet? (2007, PG)
Back to the Future (1985, PG)
Becoming Jane (2007, PG)
Bee Movie (2007, PG)
Beetlejuice (1990, PG)
Bill And Ted's Excellent Adventure (1989, PG)
Bratz (2007, PG)
Breakfast At Tiffany's (1990, PG)
Bustin' Bonaparte (2005, PG)
Casablanca (1992, PG)
Clue (1985, PG)
Daddy Day Camp (2007, PG)
Daddy Day Care (2003, PG)
Deep Water (2007, PG)
E.T. The Extra-Terrestrial (2002, PG)
Evan Almighty (2007, PG)
Fantastic Four: Rise of the Silver Surfer (2007, PG)
Firehouse Dog (2007, PG)
Game Plan, The (2007, PG)
Ghostbusters (1992, PG)
Goonies, The (1991, PG)
Great Dictator, The (1997, PG)
Hairspray (2007) (2007, PG)

If you eliminate such classics as Gone With The Wind and Breakfast at Tiffanys (how many times do you want to see those on an airline screen) then, yes, there are virtually no films that would be "non-boring" for adults.