[raaman]

Which forum or website is the best for online advertising?

[junglegal]

I would say any forum or website that has a lot of traffic. Check out popular sites and forums and advertise there.

[Treborika]

I would suggest you be careful about this as most of the websites that provide that services are scams. They take your money and never advertise your business.

[skysnap]

I think currently the AdSense is what is working out a bit more and also the system seems to be going pretty good on that note if you ask me.