Thanks everyone for the DT931 comments
I am a Sony MDR CD3000's lover. However they are closed, and have caused some hair-raising moments and missed phone calls. I was looking for an open phone that would create a lively response with tight bass and some punch.
The Senn 600's were a little too laid-back for my tastes so I auditioned the Grado SR-325, and found them rather harsh in the treble. The RS-2's were smooth with rolled-off highs, and the RS-1's were unexciting (IMO) for the price.
I think I will take advantage of Jan Meier's unbeatable price of $180 for the Beyer DT-931's, and spring for his assembled Corda Amp. I encourage people to do a search and read his fine review of the 600 & 931 coupled with the Corda Amp.
Thanks for everyone's comments.