Trigun is an interesting series, and although you wouldn't know it from the first dozen episodes, a surprisingly deep one. It's generated a fair amount of hype, and even though I'm not so sure it's for the right reasons, I do think it's deserved. Things start out downright silly, and although the series and its characters comfortably manage to hold on to their sense of humor through all but the darkest moments, it has a very definite focus and it slowly builds to an impressive climax through its 26-episode run. Most of the series has an episodic feel to it, but don't let that fool you--it is going somewhere. Like it's characters, it just isn't in a hurry to get there.
I'll start right out by saying what impressed me most about Trigun: it's good almost in spite of itself. Although usually lots of fun, it is not really a "quality" series, and certainly not a smart one; it's not wildly creative, most of the stories aren't terribly well constructed and in any case they're usually unconnected incidents, the overarching plot isn't fit together with any great precision, the drama is heavy handed, and it definitely doesn't feel as self aware as most quality stories. But despite all this apparent mediocrity, it's not only still a lot of fun but it addresses a simple issue, and addresses it in a surprisingly deep and effective manner. Trigun is so successful at this partly through the feeling of honesty that its less polished construction gives it, partly because, in the end, it refuses let things work out cleanly, and partly because of the earnest emotional heart its stories and characters.
That, in a nutshell, is what makes Trigun special.
That said, Trigun is more like three series in one. On one hand, and almost exclusively for the first half of the series, it's a classically-styled anime comedy, filled with a variety of tremendously likable characters, lots of amusing situations, and just enough depth to keep you emotionally invested. On the other hand, Trigun is an interesting examination of the Christian principles of love of life, forgiveness, and redemption (and although these ideals are held in many religions, the focus in this series is clearly on the Christian flavor). Third, tying these two very different stories together, Trigun is an unusual and reasonably creative sci-fi Western, combining an anime-appropriate weird backstory with the dusty streets and might-makes-right attitude of the Wild West, and spicing the mix up with plenty of gun-slinging action.
Impressively enough, these three different stories--action, comedy, and moral drama--all fit together surprisingly well, and the result is fun, exciting to watch, and if you're willing to get caught up in it and devote a bit of thought, even rather deep.
In the end, though, what holds Trigun together is it's characters. There are a variety of usually exaggerated and somewhat generic (though reasonably memorable, or at least fun-see Legions' review for details) minor players, but the main characters are, despite outward appearances, a surprisingly interesting and multifaceted lot.
We start out with Meryl Stryfe and Milly Thompson, two lively ladies from the Bernardelli Insurance Society who sport a particularly amusing motive for tag-along characters. They're also both over 20 and not textbook anime babes, which is a refreshing change of pace, and the two of them, despite seeming like the classic hot-headed woman and empty-headed sidekick, also have more to their personalities than I was expecting. In particular, I was surprised that Milly, of all the characters in the series, ended up seeming the most like a real person, and both her emotional character and simple strength when things got particularly brutal were among the more memorable parts of the series.
Their quarry, and the center of the whole mess, is Vash; he's the ultimate gunslinger, has the devil's own luck, and is also a total dork. There's a lot more depth to Vash than is apparent at first, not to mention an impressively unusual history, but despite the fact that he really is a badass, and carries around a huge emotional burden, he is, at heart, a goofball. At times he uses his friendly idiot persona as a defense mechanism, but for the most part that's just how he is. I liked that, and Vash's antics alone made the series as a whole into a quality comedy--his ability to take a situation bordering on serious and almost without fail turn it into an idiotic mess right around the point it crossed the line into sappy was appealing. (You can't help but love his idiotic proclamations of "Love and Peace!" in the face of drama.) His antics also saved the series from taking itself too seriously for the most part.
That was lots of fun, but more interesting (and important to the story), is Vash's refusal to kill anyone--anyone at all--and his insistence that anyone can be forgiven their past. This Jesus-with-a-six-shooter allegory is a bit odd, but the strength of his convictions makes for some very interesting moral drama toward the end of the series, which I'll get to later (that was what struck me the most about Trigun as a whole, so I'm going to harp on it). I will point out that, for a lot of viewers, the unswerving nature of Vash's dedication to his single precept will seem illogical, annoying, or even downright silly (all of which are pointed out by other characters), but that's exactly the point--this is a religious belief that isn't necessarily easy to understand.
As a blunt contrast to Vash we're given the traveling "priest" and smooth operator Nicholas D. Wolfwood. Despite the trappings of holiness, Wolfwood is far more pragmatic in his treatment of human life, and the arguments between he and Vash, as well as Wolfwood's eventual confrontations with redemption, make him a particularly interesting character in his own right.
There's also Legato Bluesummers, Vash's nemesis and an insane nihilist, who is frankly among the most frightening anime villains I've ever seen. I'll leave it at that.
Trigun takes these characters and drops them into a Western world with a strong sci-fi twist that doesn't pop into focus until the story is explained later on. Although the setting lacks a bit of creativity and seems to be loaded with 30-foot-tall mutants with no apparent reason for existing, it was still relatively well realized, and by holding off a clear explanation of how things came to be the way they are (almost certainly not quite what you were expecting), it offers just a hint of mystery as well.
In the end, though, what's most interesting to me about Trigun is the time it spends examining morality. The series, almost from the start, bluntly addresses a simple precept: "Thou shalt not kill." This simple, powerful concept has been ignored, rationalized, and explained away countless times, but Trigun digs far deeper into this idea than most stories have the bravery to do. Better yet, even though it seems to present clear-cut answers, a variety of differing opinions are raised by various characters and situations. If you spend the time to think about it, you'll see that the series is (intentionally, I'd like to think) hiding plenty of murky gray area behind obvious philosophies.
Trigun also brings up one other related issue--one that's convienently left out of many pacifcst discussions: that holding all life sacred isn't as simple as not pulling the trigger, and the risk isn't just for the person who has forsaken killing. More interesting still, though this issue is demonstrated many times (and is arguably the point of the whole series) it isn't discussed nearly as bluntly as the other moral concepts in the series, making it surprisingly easy to overlook despite how clearly it is "explainied" though a variety of actions.
You can read through Legion's thoughts for more detail on the technical aspects of Trigun, but basically it falls into the "good enough" category. The art and animation aren't spectacular and the locations aren't wildly creative, but there are some nice touches, the character designs are classic but memorable, and the quality of the production is always high enough to carry the story. There are a few impressively over-the-top fights, but these aren't really the series' strong point.
Musically, on the other hand, Trigun is more noteworthy. From some impressively aggressive electric guitar work, to a few very mellow Western-themed tunes and a pretty song that factors into the story, there is plenty of appealing music to hear. There's also Legato's chaotic industrial-sounding theme, which fittingly strattles the line between severely creepy and downright scary. The only fault in the music is that most themes are frequently re-used, but it's better than most long TV series, and it seemed to work well enough as part of the theme-based storytelling.
The Japanese voice acting is another of Trigun's strong points. Vash has a voice with plenty of whiny dweeb in it, but not in an annoying way, and the dramatic (and smooth but cheesy) parts of his persona are carried equally well. Wolfwood is also smooth, fun, and generally likable (with one of those ever-popular Osaka dialects). Hiromi Tsuru does a great, lively Meryl, although there's not much depth to the role, but that's balanced by Milly; her high-pitched voice takes a bit of getting used to, but she's likable and generally believable when she gets serious. I didn't spend much time with the English dialogue, but Legion liked it, and singled out Vash's performance as being extremely good, though personally I thought the English Vash didn't seem to be quite as much fun.
In the end, although I've focused more on other areas of the story, Trigun is first and foremost a comedy, and a funny one at that. There happens to also be more to it than that, which is an added bonus in my book. Not everybody's thing, but this is a fun anime action-comedy with enough well-done goofy gunfighting to keep anybody happy, plus an ongoing story that is anything but funny, and a conclusion with serious, powerful, and thought provoking subject matter. Best of all, the themes are comfortably compartmentalized, so it all fits together into a thoroughly enjoyable series with enough depth to make it more than just a comedy

-Akemi's Anime World