Vista falls on Day3.
Ubuntu is probably vulnerable too as its a Flash exploit but for now the final "scores" look like :
Day 1 - no takers;
Day 2 - MacBook owned in slightly under 2 minutes via a Safari exploit;
Day 3 - Vista owned in a bit over 4 hours via a Flash exploit
Ubuntu still standing.....
http://www.theregister.co.uk/2008/03/29/ubuntu_left_standing/