What blades are you using now? If you are using MK blades, you may want to stick with MK so you don't have to adjust to a different profile/rocker shape. If you are using WIlson blades, the most popular blades for senior level skaters seem to be the Gold Seal and Pattern 99. You can either stick with WIlsons or try one of the top end Ultima blades or Paramount blades, which are actually based on the Wilson profile (I think they are based on the Gold Seal blade). Ultima blades are cheaper, but Paramount blades are lighter and don't have to be sharpened as often.
Also, what is it that you don't like about your current blades? That will affect your choice of new blades as well.