i'm using CamStudio - it's free and working with mah audio (fraps doesn't record mah audio). http://www.youtube.com/watch?v=jnrVSiIGXLo <--- but i used wrong codecs so quality sux ;o.
you can't just ask, there are many progams and many opinions you'll have to try some yourself if you're not lazy so finally you'll know what's the best for you