Which Online Marketing niches do you feel are saturated?

PPC and affiliate marketing programs are everywhere on intenet

Weight loss programs are everywhere. But then again, why is that so....because there is a market for it!

Health products, its a very competitive market.

Hyip metrix, social network creation, weight loss pills, webhost provider,

I also agree to @Osawald

Anything not making money!

Saturation is a myth. If you have a product that is in some way better than the ones out there, you'll surely find a market as long as you choose a niche that has people willing to pay for what you have to offer.