OK, here are some funny AdSense ads from my web sites:
- on a site where I mention a name of the person, AdSense serves an ad to the software that has the same name as this person, but nothing to do with the topic of the page
- AdSense sometimes shows ads of competitors of gadgets I actually describe on given page, although I am very sure that no keyword related to competitor is present on my page (maybe AdWords advertisers on purpose do it, to show their ads on pages related to competition? I would call it anti-targetting = targetting but exactly opposite to what is given page about - I am not sure whether it is funny or regretful)
- on my pages related to scientific stuff, not at all mentioning anything religious, I see AdSense ads from religious organizations, that seem to be saying "this whole scientific cr~p is nonsense, read about God"
- on one page I was describing certain software program and the AdSense banner has taken literally what this page was about - I cannot betray details, but it was like it: I am describing a game/simulation about managing football team, and AdSense offers me in the banner "buy your kid a good ball and football shoes"... it was funny and tricky.
................ but generally I am quite satisfied with google targetting.