FOLLOW3R :
FRAPS is what I use. It's unbeatable to be honest. I tried everything elser but It just stands out....
Do you use vista or windows 7?Just know from Wikipedia-
"In order for Fraps to take pictures or capture videos onto their system, users must first be using a program that uses DirectX or OpenGL as a core runtime system. Programs that run in Windows without DirectX or OpenGL are not supported, and therefore Fraps cannot capture desktop applications under Windows 2000 and XP. In Windows Vista the Aero desktop runs through DirectX and can be captured by Fraps."
FRAPS is Best for sure,excellent sound capture as well as video.But it only captures Gameplay not normal screen capture for me as I use xp.