For track days, any of the race tires from the major manufacturers would work just fine. I happen to be on Pirelli's and have nothing bad to say about them, great tire. Bridgestone BT003R, Michelin Power One (I've heard good things but no experience), Dunlop makes several, all more than adequate.
If I had to choose a Street/Track tire it would be Dunlop's Q2. This tire is hard to beat for the hard charging track day enthusiast and canyon carver. As close to a race tire as you can get with a street friendly personality. Bridgestone BTOO3R/S would be my second choice. May be as good as the Q2 but until someone shows me a better tire, the Q2 is at the top of my list!
I'm a little leary of the new Michelin Power Pure since it's an upgrade of the PP2ct. We'll see how they perform when the track season gets going?
Mind you, these are only my opinions and preferences!