Normally, when an anime series or movie based off a manga is made, it's usually inferior to the manga original. Before today, the only anime adaptation of a manga series wherein I thought the anime was better was Death Note. Today, I have discovered a second anime based off a manga where the anime is superior.
Its name is Trigun.
I have bashed the Trigun manga in the past, yes. You must understand, though, I don't dislike the setting of Trigun, nor its dual-personality hero. However, the manga's artwork is rather rough, the action sequences were confusing, and since the sound effects aren't translated, that only added to the confusion. The anime, on the other hand, has much better action scenes, and I even got a better understanding of the characters. I've only seen the English dub, and while a few characters sound great, (Especially Johnny Yong Bosch as Vash the Stampede.) a few players sound over-exaggerated. Its dub job may not be as good as, say, Cowboy Bebop, but anything that beats the majority of Saturday Morning cartoons (be they anime or not.) is a winner.
True, Trigun the anime may not span as long of a time period as Trigun the manga, and may have less characters, but damnation, it works better on film I tell you!
P.S. I think Naruto the anime is as good as Naruto the manga. The Naruto manga is uncensored, while the Naruto anime has better artwork, and better-looking fight scenes. As for which version is better, it's really a matter of taste, if you ask me.