In all seriousness? I know it's the purest pipe dream, but I would love to see one or more sequels to Master And Commander: The Far Side Of The World. Ideally with Peter Weir back directing, and the whole cast back. After all, there are twenty books (well, and part of a twenty-first) in the Aubrey/Maturin canon.
Personally I think The Fortune Of War would be an awesome basis for a film. Although it technically takes place prior to The Far Side Of The World in the books' chronology, the fact that a) they changed the setting of the TFSOTW from the book's 1812 or 1813 to 1805 for the film and b) The Fortune Of War's plot is inextricably bound to the War of 1812 means that a sequel based on that novel is still feasible. You've got a great plot with a lot of intrigue, a couple of kickass sea battles (actual historical battles here, to boot), and you get to really delve into Stephen Maturin's other life as a secret agent (which was, apart from a subtle throwaway line, ignored in the first film).
From a practical standpoint, the biggest problems are that Jack Aubrey spends much of the story as an invalid (which might not sit well with Russell Crowe's ego, not being the focus of the story the whole time) and that it actually presents the Americans as antagonists (albeit respected, honorable, and sympathetic ones... and the French are still the real villains). The 'Americans as antagonists' issue was what inspired some of the changes in TFSOTW's plot and setting--the French privateer of the film was an American naval vessel in the book. It was felt on some level, we find, that American audiences (especially in a post-9/11 timeframe) might be turned off by a film in which Americans are the enemy.
Anygate, it's not liable to happen, I'm sure. But a guy can dream.