Uh, the creative process really requires you to come up with your own ideas. Honestly, if you have to ask others what to write about and need others to create for you, then perhaps youa re not skilled enough to come up with something on your own. I see a lot of quesitons like this, and if you cannot create your own work (creating is really a very personal thing), then you might want to switch to something else. If someone else gives you an idea, then it really is not your own. Will you want them to write the first chapter for you too? No offense, but I think you need to think about these things.

I suggest the books Uglies, Pretties, and Specials. They are for teens but are wonderful books. They are by Scott Westerfeld if you are interested.

Have you read the classics like Moby Dick, Treasure Island, or Huckleberry Finn? They are all classic examples of adventures books.

I also found this great site. Check it out. It is an article about the top 100 adventure books. Very cool. with titles like: Travels, by Marco Polo (1298), The Spirit of St. Louis, by Charles Lindbergh (1953), The Voyage of the Beagle, by Charles Darwin (1839).

I know they are old books but these are classic stories about a time lost, about people and places long gone from our reach because of time.

Have you read Maximum Ride : The Angel Experiment
by James Patterson? This is the first in a series and has lots of adventure and mystery. It is the story of a band of kids who have escaped a lab where they were bred as 98% human and 2% bird.

Elkhana and the Prince of Rhenar
The Assassin: Attack On America, by Robert Mansfield

(The Voice that Challenged a Nation: Marian Anderson and the Struggle for Equal Rights
Russell Freedman)

Any Scott Westerfeld book or Jules Verne. Eragon and Eldest are fantasy books but there's a lot of adventure and mystery.