Right from childhood, I have enjoyed films which belong to the thriller genre. As a kid, I would read novels written by Agatha Christie and James Hadley Chase.
On a serious note, I just enjoy exploring the unconventional. I like Alfred Hitchcock; I actually grew up watching his films. A thriller gives you much more scope of exhibiting creativity in terms of playing with the camera and sound, as against a typical love story.
It is unlike the quintessential thriller where someone is up to something and the audience is speculating. 'Johnny Gaddaar' is the opposite of a thriller. In this case, the audience knows right from the outset what transpires and who the likely culprit is. It is a suspense caper.
I love songs but am inhibited to have my characters burst out to express themselves through songs. I use the route of using old songs at the right places.
As a filmmaker, I tilt towards stories which are crime-led.