Artist Jón Kristinsson runs a site called Point n' Clicking, where he posts images of famous adventure game characters (or casts). Some are recent, some are old, some are very old, but all are fantastic, capturing the spirit and tone of the games they're paying homage to.
Some highlights below, but you really check out the whole collection on Kristinsson's site, where you'll also find links to buy them as prints.
Point n' Clicking [Site]