Which Skins give a small advantage?

Some champion's skin can make skillshot harder to see, harder to differentiate from an auto attack etc

I am a anivia player and I found that the E is slightly harder to notice and differentiate from the auto attack with the black frost anivia skin.

For singed, for instance, the surfer skin has a green poison, making it harder to see if you have in a bush etc...

I think there was one nidalee's skin that would make the spear much harder to see.

Blitzcrank's Q has a smaller animation, so it looks like the skillshot is smaller than it it. This is only valid on the I-Blitzcrank skin though. (from Jaimin N on this thread)

Is there any other skin like this?

PS: I know this doesn't make a huge difference, but it actually does sometimes. And I thought that those skins tend to be the most expensive ones. Maybe is it on purpose? (I might be paranoid though)