Uber meaning the ultimate, above all, the best, top, something that nothing is better than. So when you're saying something is uber it better be something crazy awesome. If not then quit using it. This word is uber in itself.
Sniggle meaning nigga also friend and compinche(pal).
So ubersniggle means a best friend. This person is the all time friend none are above her/him.
Oh!! You rock my socks you're my freakin' ubersniggle!