If you drive ALOT on the street or commute in your car, the Nittos are your best bet. They are decent in the rain, provide good handling, and last over 10K miles for most people.
If you drive a good bit on the street, but don't depend on your Mustang to commute with, BFG drag radials are a great choice. They hook better than the Nittos, but flex more and provide worse handling. They are horrible in the rain and only last about 3K miles, if you're lucky.
If you don't drive much on the street and take it to the track alot, the ET Street radials outhook the Nittos and BFGs. They handle for ****, won't go at all in the rain, and don't last very long at all. But they hook VERY well.