A lot of people seem to agree with the A5 Sportback, and it's indeed a pretty great car, quite handsome, too! Plus, having that Quattro all-wheel drive would be a boon for all-season driving, and with added luggage space compared to the S5.
Though if taking fun into perspective, a rather subjective one, I think I'd choose the 4-Series, just for the dynamics, and pure smile factor :-D
