Man, you're lucky with your adds - and that might be because of google seeming to take language / location into account.
Currently, I have adds for (translated) "winning an iPhone 3G in my favourite color ! Click here" with a most annoying mouse-over sound.
Another non-favourite (and, unfortunately very common) add is the one telling me to take a test to know my death-date - which, too, does have a very annoying mouse-over sound effect.
Free MMORPGs (Last Chaos, Shaya, Florensia, etc) make up 95% of the rest.