1. Mesothelioma 2. Viagra ( Adsense banned) 3. Games 4. Funny stuff 5. Chat forum Suggestions are invited I need this information for an article.
It's always a safe bet to spread the risk / volatility when monetizing a website, no matter what the niche. This means using a combination of CPM, CPC ads, (google), direct sales to related sites (if can make more than adsense), affiliates (might not be exact match but there HAS to be a related affiliate), and if it's a blog perhaps sponsored posts.
Affiliate sales and adwords have always worked for me. Just make sure you don't turn your website into one big advertisement. You loose more revenue by not making sure everything flows smoothly then not.
1. Mesothelioma (adsense very high cpc) 2. Viagra (find a dropshipper and create an online store) 3. Games (in the game industry people use adsense mostly, but you need to have big traffic as its low cpc) 4. Funny stuff (adsense again, target high traffic keyword and you will do well) 5. Chat forum (this one it depends on the niche, if it is a internet marketing forum then you can sell clickbank products targeted at them)