These are scans from the Trigun Roman Album, most can be find on other sites (or that used to be the case, dunno if it is anymore). Another gallery I ought to go through and rescan so that they're larger and higher-quality.

cover - Some of the writing was cut off to get more of the image.
poster - Vash and Wolf on a poster featuring mainly M&M
cats - Vash and that rabid-looking bunny/cat hybrid.
over-the-head - Just a boy, his gun, and his glasses.
BDN - Vash and his favorite Neon companion.
knives - Vash, the cross, both guns, and Knives lurking.
insured! - A big Vash with smaller insurance girls.
contrast - one of my most favorite images.
gun - just his silver gun, but I liked the technique.
kick - a midair gundrawn kick. That's talent.
pretty - Vash holding Wolf's cross with Knives again.
decartes - Vash sitting on Decartes' head.
duo - Vash and Wolf with their weapons of choice.
family - They're all just one big happy family.
big gun - agitated Vash with Legato and Knives in the background.