I remember turning 21 and "investing" in a bottle of whiskey. I think it was Jim Beam. I mixed it with Dr. Pepper, and it almost lasted through the weekend.

On the other hand, if you really want a good bottle of whiskey to commemorate this occasion you won't remember a year from now anyway, go with either Maker's Mark or Woodford Reserve. Do yourself a favor, and stay away from the blended scotch. There's a thread somewhere in here about single malt scotch, check it out. I personally had to evolve from whiskey to scotch, and that took at least 5 years. I still keep a bottle of Maker's Mark on hand, and usually keep a bottle of Bacardi 151 (for cooking) on hand, but scotch is the prevailing brown liquor in our cabinet these days.