The humor is subjective of course, personally, they never made me laugh out loud, but I'm not going to take that into account. I'm sure there's people out there who enjoy the jokes, I'm just not one of them. What I am going to critique you on, though, is the absolute lack of evolution in your work.
Honestly, the voice-acting is the only thing that has been consistently decent in this old-baked series. The art and animation have been stuck in mediocrity since episode one. When will you finally decide to pick up some correct shading, drop the ugly strokes and shape tool. I can understand if you're not an amazing artist, but at least try doing something new once. After so many years, you're still animating a stick figure that doesn't even have an actual mouth, just his teeth bumping up and down.
Using motion tweening is fine. There's loads of cartoons that use it, such as Madness, South Park or the animated segments in the recent Alice: Madness Returns. However, all of these cartoons had a distinct style in art direction. In this series, it seems incredibly cheap and not blended in well at all.
This is critique to help you improve. The series is growing stale, and you know it is. Try something new. Anything that could possibly make you, as an artist, grow and not just let you stagnate on the spot by having Edd Egg act annoying, yet again.