A long time ago the city of July was destroyed by one man, Vash the Stampede. Although no one was killed there was a bounty of 60,000,000,000$$ put on the mysterious gunman. Now, Many years Later the Bernadelli Insurance agency has sent Meryl Stryfe and Milly Thompson to find Vash the Stampede, and make sure he doesn't do any damage. When they find him they are surprised at how this goofy peace loving gunslinger has managed to live through so many attacks. However they soon find out that Vash is very good at what he does, helping people survive the numerous bad guys that attack the innocent. While protecting others, Vash seeks Knives, a murderer, so that he can settle the score for the many horrible things Knives has done. However Knives is ready with his gang of killers, the Gung-Ho-Guns and their leader Legato.
That's Trigun, but that leaves out such important characters as Rem the woman who taught Vash to be the way he is. Also Wolfwood the gun toting preacher who befriends Vash and helps him protect the innocent at any cost. This series starts off to be almost a pure comedy with a little action, but it evolves into a lot more and still keeps its fun. If you want to find out more of what Trigun is check out the episode summarries or the manga spoilers.