For me, it happened about a month or two ago, when a couple of my classmates (I'm studying Japanese) talked about dramas and they were so in love with Rich Man, Poor Woman.
I wasn't very interested at first, I only watched it because I wanted to try a j-drama... but yes, I fell in love with RMPW! :) And then, somehow, I couldn't help noticing that Arata Iura is soooo handsome!! So the next two dramas I watched were Mitsu no aji, and Chase. :) He's seriously the most beautiful man ever!
My classmate's next suggestion (more like "you HAVE TO watch it now!!") was Hana yori dango, and last night I watched 6 episodes... So even though my classmates, or especially one of them, made me watch my first, ARATA made me want to stay in DramaLand... and Hana yori dango proves that I like it there even without him. ;)