In my short Thanksgiving travels, I managed to complete the audiobook of Edmond Hamilton's The Three Planeteers, originally published in the January 1940 issue of Startling Stories. Other than providing the inspiration for the name, Dumas' novel has little bearing on Hamilton's work.
In a future (Sometime in the 28th Century, I believe. An exact date isn't given.) where humanity has settled all the worlds in the solar system and gradually adapted to them. The fascist dictatorship of Haskell Trask has spread from Saturn and its moons, to all the outer planets, forming the League of Cold Worlds, which now menaces the Alliance of the inner worlds.
The titular trio are the most famous outlaws in the solar system: John Thorne of Earth, Sual Av of Venus, and Gunner Welk of Mercury. It turns out they aren't really outlaws at all, but special agents for the Alliance, pretending to be criminals so the Alliance has plausible deniability regarding their actions against the League.
With war looming, the only hope of the Alliance to defeat the massive League war fleet is an experimental new weapon which requires the ultra-rare substance radite to work. Good news is there sufficient radite on the trans-Plutonian world of Erebus. Bad news is no one has ever returned from Erebus alive. Well, no one except, it's rumored, a former renegade turned space pirate. Said pirate is now dead, but his daughter reigns as pirate queen in the Asteroid Belt.
Besides the classic space war plotline, Hamilton gives a lot of space opera color: "joy-vibration" addicts, hunters in the fungal forests of Saturn, and the deadly secret of Erebus. It could be easily shorn of some it's old-fashionedness and moved outside of the solar system. Pieces would be easy to drop into Star Wars or any other space opera game.