Adsense is still the best by a country mile but can be a poisoned chalice. Newbies install it and expect to make a fortune overnight, this won't happen and anyone who tells you it will is a liar.
Adsense works well if you have an established site with unique and useful content but even this isn't enough. You need "TRAFFIC", pure and simple! If your traffic is low your income is low, there are no exceptions.
I get frustrated when the "Gurus" promote the same old bullshit, I get angry when I see genuine people falling for their lies. Adsense will and does work but you need to work also, once you taste success with Adsense you have to be careful you don't become complacent. Work at producing useful content everyday, work with Adsense set-up to maximize revenue and stay white hat. Take the time to read the terms of service; it's boring but important!
The next important point is don't rely on Adsense to pay your rent, diversify so if Adsense does fall out with you it will be a distraction instead of a disaster. There are plenty of alternatives (see my sig) you can use but the same rules apply, you have to put the work in to benefit from them.
All the best
Rob