Hamilton for me, don't think Rosberg will match him this year either. Ferrari looking strong in testing so far, but I suspect that Merc is only gathering data and not even trying to set fastest laps yet.
Can't wait to see what McLaren brings this season, realistically I don't think they'll be challenging at the front this season, and testing so far has not proved too positive, but things change fast in F1 so here's me hoping that car is a proper fast runner once they work out the kinks!