I am frankly shocked to see negative reviews about adsense... It has been a God-Sent for me, and a healthy source of income as well. I can honestly say that in 3 1/2, almost 4 years, never once have I encountered an issue with ad serving, technical difficulties, or payments... they have been 100% on point, consistent, and by far the most lucrative of all of the "alternatives" (if you can call them that, as no ad network or affiliate network to date can hold a candle to Adsense revenue)... Don't put any stock in the negatives against Adsense... Based on what the ones I read on here say, it looks more like they either tried to get away with something and got caught or paid little or no attention to the guidelines, did whatever they wanted and actually believe that they aren't responsible for following rules the first time around if they never read them... ridiculous... bottom line, they all appear to have done things they are not supposed to do with an adsense account and got penalized for it, and are now mighty unhappy because AT BEST with the next best 3-4 networks COMBINED they're probably making 10-15% of what their Adsense Revenue generated alone for them...
To end on a note of credibility, I'll give a specific example. Someone above whined that "All I got banned for was visiting my site and check a ad link" - Every part of that statement is something you're NOT supposed to do on Adsense... even after having gotten banned for precisely that, it didn't seem to sink in...
There's a reason Adsense is so hard to get into, and is actually regulated once you're in... IT"S WORTH IT - don't let garbage producers like these morons deter you... Adsense is GOLD