The obligatory links section. Here's a few of the more interesting pages on offer, as well as some buttons to link back here if you're so inclined ^_^.
Haunting Garden - Lookie! Knives has a shrine of his very own! There's some Knives info and some fanfics, but don't go if you don't wanna be spoiled ^_^
Up in Smoke - A really nifty page with screencaps from every episode, e-mail addresses (I would get vashstalker, but I dislike zzn.com), essays, and other stuff I can't remember at the moment.
Happy Donut Land - A place to adopt adorable Trigun Chibis ^_^ I couldn't help myself.
Make a Little Lightbulb in Your Soul - This is a sweet page. It's got manga info, translations for interviews, translations for drama tracks, and monthly Trigun chapter translations. Go and worship NOW.
The Hastily-Assembled Nicholas D. Wolfwood Shrine - Nifty shrine to Nicholas D. Wolfwood. Has much in the way of info and images.
Love and Peace! - A Trigun site focusing in on the Audio/Visual aspect. Go read the Millions Knives/Sting conspiracy. NOW.
Trigun Maximum - A good site about every aspect of the show maintained by a very nice Japanese woman. Has just about everything you could possibly want in the way of Trigun.
Cheers! - A Doujinshi page leaning on the Trigun side, but other series are also there (like Utena). I love Doujinshi!
Sand and Light - 'Tis a very good fanfic continuing the series past episode 26. If you know me, you know how much I love fanfics ^_^
Trigun Realm - This is a massive, MASSIVE information page for Trigun. You can find a lot of things here, such as a drinking game, kuroneko sightings, and just about everything about the Trigun tv series.
Strangers with Donuts - A nice Vash shrine with a lot of random info and many things to do. A lot of the other Vash shrines I had linked here vanished ;_;
Red Coats + Silver Guns - A shrine to two guys who have a lot of similarities, Vash (of course :p) and Kenshin from the series Rurouni Kenshin
Angel Intersection - I thought I had linked this awhile ago too... This is a collective housing a Wolfwood shrine, a VashxMeryl page, and a minishrine for Rem. All are exceptionally well done pages.
Gunshy - Hooray! The Trigun manga scans site is back! This site has scans from both Trigun and Trigun Maximum as well as some artbook scans and some miscellaneous other things. Also highly recommended are the author's Vash shrine and this Knives shrine that's along the same lines and designed by the same person, but the excellent content is written by someone named Jai.
Trinut - This is a growing forum community dedicated to the Trigun TV series. At the moment it's pretty nice, but go ahead and join if you wanna talk Trigun and contribute to the discussions.