Welcome to The Perfect Loop. I enjoy gifs that loop perfectly without jumps. I will give you an example:
Why? You can tell when the gif stops and starts.
Also not acceptable:
The girl in the middle loops perfectly, but the background does not.
You may submit if you would like. Although, I am quite picky about what gifs are considered perfect. If only one element is perfect and the background is jumpy, it is not acceptable. The entire gif must be completely perfect.
Anal? Yes. OCD? Yes. Satisfying? Very. I strive to create never-ending pages of gifs that I find that please me.