I always liked beer and drank plenty of it for many years, but it wasn't until 1990 that I had something that wasn't a (real) German Pilsner/Lager or an American Adjunct Industrial Lager.
And that beer was Young's Ram Rod Ale. I took a sip and it blew me away. To this day I clearly remember saying to my friends, "Now this is how beer is supposed to taste!"
I had been drinking beer for 6-7 years at that point, but never had a full flavored Ale before and that really opened my eyes. I've had plenty of amazingly good Lagers in the states over the past few years and tons in Germany since the mid-80's but there's absolutely no doubt that my taste buds side with Ales immeasurably over Lagers.