Why always braided line?

I'm just curious as to Why do most of you guys prefer braided line over Fluorocarbon or regular Mono line. Mono and fluorocarbon just feels so much more smother on the reel than the braided line. Should I just trash my old line and try out some new type of braided line. Just wondering what the difference is going with braided. Is there a particular braided line that I should try. Reason for asking, I need to go buy some new line today.