hmmm... odd that I hadn't seen this thread before.
Anyway, I'm not going to put down percentages, so here goes.
Part Basque, English, German, American, Greek.
My great-grandparents on my mum's side emigrated from Greece to the US (went through Ellis Island and all). There they had my grandfather, who later moved to Venezuela and married my grandmother, an English lady of German parents and had two kids, one of which was my mum.
My dad's side is almost completely Venezuelan, save from my great-great-grandfather, who was from Spain (Basque Country) and moved to South America in the 1600s. At some point in the bakground I'm sure it can be traced fully back to the motherland (in our case, Spain), but up to now, this is it.
I was born in Venezuela and spent most of my childhood between Venezuela and the US, although I was schooled in Venezuela until college which I did in the US. Since 1995 or so I've been moving around though.