I didn't start making it a point to drink until January 2007, which is when I decided to make buying a bottle each month part of my budget. I didn't buy Scotch until Fall 2007 when I bought a Glenlivet 12, both because it was commonly available and because it seemed to be Tony Soprano's drink of choice.
Until the start of this year my purchasing preference was flavored liqueurs like Galliano, Wild Turkey American Honey, Barenjaeger, Drambuie, etc. But watching shows on TV like Modern Marvels, which sometimes focused on whisky, made me aware of the difference between blended Scotch and single malts. Sometimes specific distilleries were detailed, such as Laphroaig or Glendronach. In these cases this gave me targets to look for, which is how I discovered the glory of peated malts (through Laphroaig). I never met a Scotch I didn't like, but peated malts are much more enjoyable to me than other single malts. If there was a large selection of peated brands I'd be tempted to never buy a non-peated malt.
Funny, but I don't particularly like Irish whiskey or American whiskey, especially not bourbon. I attribute it to the flavor inherent in barley vs. the flavor of corn. I'm a barley type of guy I guess.