I really like the IM50, glad I got rid of the TripleFi and made a little profit from it.  I like the TripleFi10 but it doesn't clip onto my ear that well despite trying all different plugs I can't get it not fall out.  So far the IM50s with the Comply foam plugs are doing it's job of staying...

I think the biggest thing going for Beats by Dr. Dre is it's the only line of over the ear headphones that is acceptable in looks and styling by the masses.  It's sleek, got the ipod like curves and lines.  People who never purchased any headphones over $20 suddenly went all out for a $200-300...