I don't have a lot to spend on headphones now, to be honest. Around $150, I find that the M50 is a safer bet because I have listened to them.
I also audited Beyerdynamic DT770, DT880, Shure SRH940, and Sennheiser HD25-1 at the local Guitar Center, and I wasn't terribly impressed with any of them, save for the DT880, which I found to be quite good, but it was out of my budget. My dad's M50 actually sounded to me like it had more clarity and wider soundstage than the DT880. Perhaps it was merely because my setup (iPhone 4 + Fiio E7) wasn't enough to drive the higher end models. But all in all, I found the M50 to fit me best. Or to be more precise, my dad's M50.