I have used http://www.adbuytraffic.com/index.html several times. They do send traffic and one of their sources is a google owned site. If you are serious, sign up with their wholesale http://www.trafficspecials.com/
I would not anticipate a great amount of paying traffic for online gaming.
My biggest sucess was in adding traffic to http://www.casinosca.ca with some canadian only traffic.
I also have had some modest success with acne on http://www.acnelinks.com It did increase and resulted some google ad sense purchases; but it still was a money looser. ($20 in traffic to get $5 in Sales).