There's so many possibilities!

Riot, we all know you could do so many things with so many different champions when it comes to skins... Especially my favorite champion, Quinn; here's a few concepts I found that I think everyone else (that plays Quinn or not) might appreciate or enjoy looking at as much as I do.

Bilgewater Quinn: http://i.imgur.com/TPenyyQ.jpg

A Harrowing Quinn: http://i.imgur.com/xpIa97Y.jpg

Dino Quinn: http://i.imgur.com/aQCVJT0.png

Night raven (or Blood knight) Quinn: http://i.imgur.com/eFji0TA.jpg

Some type of futuristic Quinn: http://i.imgur.com/w5V3iB9.jpg

And I saved the best for last, here it is ladies and gentlemen.

A different type of futuristic Quinn, but cooler than the previous one linked: http://i.imgur.com/u9g9W67.jpg

I'm also pretty sure I've seen a poro-themed Quinn skin idea somewhere laying around the internet before, as well as a special forces Quinn themed skin, and a hextech Quinn skin too. Hope you enjoyed the concepts