Like none of them.
First avatar is boring,light source is too strong nothing's going on there
Second one is nice but quite simple,placement of the image is off...you could place it more to the right so there was some outer space and it wouldn't look so much zoomed as it is.
Finally,third....Bazz's already told you about scan lines,other tip : do not use dark borders on bright avatars.On dark ones - yes ,borders may work but on colorful avys - only light and matching with color borders ,otherwise they can be an eyesore.
If you are not sure about adding a border ,don't add it.Some avatars look much better like that.
Keep trying man,everything else is a matter of time and patience :3