IMO, the very BEST dies I have used are Redding and Forster. I especially like the Forster Benchrest bullet seating die.

RCBS stuff is also quite good. Lyman, Hornady, and a number of older brands will work too. And even Lee dies are acceptable, especially if you are not loading thousands of rounds.

Recently, I have taken to buying dies off e-bay, especially when it's for loading a caliber that I need right now, but won't use much!