Best intro to a song

[Axeknight]

Welcome to the Jungle - Guns n' Roses
Those opening chords launched Guns onto the scene and they were awesome.

Mama Kin - Aerosmith
Extended intro from Joe Perry. Love it.

Sweet Child O' Mine - Guns n' Roses
One of the best riffs ever, and the solo is probably the best guitar solo ever.

NIB - Black Sabbath
This whole song is just awesome. Some people say my love cannot be true... Baby give me your love and I'll show you... I can give you those things you thought unreal... The sun the moon the stars all bear my seal...