I made quite a few ads while at IDG.net, for IDG.net-run sites, other IDG business units looking to score some cheap labour, and an occasional outside client. The first involved the most work (no copywriter, not a lot of $ for stock images), almost total control and was therefore the most rewarding. The latter two, not so much. When it comes to advertising, the less taste people have, the more they tend to pile on the impossible demands.
The selection below (non-clickable) represents the handful of ads, both rejected and run, that I actually like.