I used to use Moho for animation. Though the program is very powerful, I found it difficult and time consuming to create even simple animations.
Recently I've been playing with CrazyTalk Animator 3.3 (Reallusion is about to release Cartoon Animator 4). This program is much easier to use to create fast videos.
There are also programs available for doing explainer videos. Animated white board presentations (Doodly) and explainer video software is less powerful but even easier to use.
So, what kind of animation do you want to add to your videos?