Mostly, the Trigun Roman Album has info on the anime, with some manga artwork in the back. Not a great artbook, but 'twas my first, so I still treasure it. These are scans from Vash's character profile and the miscellaneous episode pics that had Vash in them. Think of them as screenshots, except scanned. Not that large or high-quality, another gallery I SHOULD go through... but it took me so long to do these images, I don't know if I will.

skin - Vash pointing his gun at you.
silhouette - Vash silhouetted against the moon.
pointing - Vash points confidently.
somber - Vash looking serious.
puppy - stripped naked and barking like a dog.
close gun - A closeup of his gun.
midair - Deep Space Midair Gun Action.
sad - Trying to decide whether to shoot Monev the Gale.
scary - Sometimes he's just scary...
dodgeball - the deadly dodgeball head in action.
tanked - a little plastered.
manuever - Vash dodges something, I'm sure.
youth - a pic of Vash and Knives as kids.
parting - Rem and Vash part ways for the last time.
tears - Vash cries after loosing Rem.
collage - Vash and Knives fight as kids.
kids - More Vash and Knives as kids, collage-ized.
apple - Vash and Knives gaze at an apple, still kids.
reunion - Vash takes up arms again after August.
glitter - Vash sparkles tucked in bed.
pain - Vash clutches his arm in pain.
teamwork - Wolf & Vash take care of business.
hug - Vash gives Lina a hug.
reaction - Vash while forming the Angel Arm.
babies - Vash and Knives' baby picture o_O;
look - one of those serious looks
glint - the glint off the gun
hide - hiding behind rocks
thumbs up - Vash reveals his goofiness after a fleeting moment of seriousness
pushup - pushing the glasses up
sincere - a sincere look, probably hitting on someone ^_^
yup - I was right, there she is
bishounen - things go floaty
flathead - Vash gets the style washed out of his hair
dejavu - a girl dressed like Vash!
weep - and the bandit gently weeps with Vash ruining the moment in the back
mouth - extreme closeup of Vash's mouth
holdup - Vash against the odds
serious - interesting shot of Vash aiming
... - one of those looks
hand - Vash dismissing something... maybe
exasperated - someone stressing Vash out for a change
sun - rays of sun beat down on him
laugh - drunk again
trashcan head - closely related to dodgeball head
drinking - in the act of getting drunk
bishounen - sparkle sparkle
glasses - Vash puts on the glasses
looking - looking down the barrel of his gun
out of focus - out of focus on a split screen as he draws his gun
ketchup - laying in a pool of... blood?
scary - a scary face
...scary - just a frightening face
casual - headshot against the blue sky
serious - gets serious... or something
vogue - striking a pose
twisted fight - fighting with that scary costumed man
covered - in a loose brown wrap
hug - Vash hugging the plant manager
holy - talking with the plant
light - looking from the plant's pov