[Craigster75]

  can anythig beat logitech in sound quality and the least leakage
(my spelling is off today)
 
Happy Listening

There is a distinct difference between sound quality and least leakage.  The UE6000 has really come down in price recently- you should be able to pick them up for under $100.  I would say that makes them the best value of the bunch.  If you want the best sound quality, that is subjective.  My personal preference would be the M-100, but the UE6000 is certainly a good headphone, just a bit too much rolled-off treble for my taste.