It really depends on the amount of frames that are going to be in the animation. Since the animations that I do even for simple animated screenshots do not have that many frames, I use AnimGet, then take all of the frames to make an animation by putting them into a sprite in Game Maker then saving them as a GIF, I then use MS Gif Animator so that it loops.
If you screenshots contain a lot of frames and you still want to save topic space, I would suggest just making them videos, uploading them to something like YouTube, and then showing them as embedded. Screenshots do not have to be perfect, their use is really just to give the general idea.
