I have had great success with Project Wonderful and I recommend it highly.
I spend about 30 bucks a month, but I get a good number of hits. With Dr.McNinja I went from 96 visitors a day to about 350 per day. I cant complain.
And the good thing is...most of them seem to be sticking around.
I don't get as many hits with Scary Go Round, but I am looking for that specific target audience...folks who like supernatural weirdness. They are the ones I want to keep.