Yellow
Seriously, Vin Jaune (Yellow wine) from the Jura is my favourite wine. Technically it falls into whites I guess, but my beloved Vin Jaune has nothing in common with your average chardonnay.
This is closely followed by dry sparkling roses. I can't get enough of them, whether they're from Champage, Alsace, or Canada (Henry of Pelham makes a gorgeous dry sparkling rose).
But I love both reds and whites, it really depends on what my mood is at the time and what I'll be having with the wine. In general my tastes run more towards old world wines.