@[email protected] 3rd edition certainly was a turning point in marketing D&D. They started using "iconic" characters in illustrations for a given character class in the rule books, putting them in advertisements such as this one, and 2 years in they were selling novels all by a "T. H. Lain" company pen name about those characters. It looks like Mialee (the elven wizard on the right) was sort of brought back for a 5th edition illustration, but during 3.5 WotC created a larger pool of iconics, so the originals saw less use and 4th edition didn't have any of them.
This illustration was drawn by Todd Lockwood and used on the cover of the 3rd edition starter box with simplified rules. The red dragon in the background was reused for the cover of an album WotC commissioned from Midnight Syndicate.