IPAs need to be drunk as fresh as possible. The longer an IPA sits on the shelves the more it loses the fresh grassy and floral notes and the more the bitterness starts to creep in and overpower everything else. My brother does some brewery work and the difference between an IPA that has been sitting on a shelf in a bottle shop for 2 months and one that was freshly bottled that day is crazy.
My heart is with sour beers and barley wines at the moment though. So delicious.