I have been pretty pleased with widgetbucks so far. I tried running NeverBlueAds rotating banners on it and picked up a few leads, I ran Valueclick on it for a while but I just dont have enough traffic for it. I ran YSM for a while but those ads are terrible, I was kicked out of adsense for "fraudulent clicks" but that worked well for a while. So, Right now widgetbucks is doing well. You should probably test different networks out. That is the best way to do it and see what works for you and your blog.
Everyone is talking about widgetbucks lately. Since I never used them I won't say anything, still there are other options. If anyone uses widgetbucks please tell me how it goes.