My headphone - the Sennheiser HD201

Naturally the previous headphone amp was purposely built to drive this, the HD201.
I'd say the HD201 would be the best bang per buck headphone. Of course there are 'better' headphones out there.. and obviously more expensive. I paid RM120 (equiv. to USD36, early figureof 54 was wrong..)
I do not use headphones all the times, rather occasionally when I need the privacy and this is where the HD201 shines.. mostly it is used with my Sony's S7000 DVD player which being the flagship model during it's heyday, has the best built-in headphone amp…
To really enjoy the dynamics and the potential of the HD201, a headphone amp is really recommended, DIY or otherwise!

Here's a review of the HD201, and here.
More info here. Very interesting read.

Pros:
Light weight. You can wear them for hours at length!
Very neutral sounding with slightly bright overall but not too 'fatiguing'..
Very good sound esp. the bass.
Cheap. Best bang per buck

Cons:
The cable can be a tad too long and can tangle things..
May required amplification to realize full potential if your puny little mp3 player don't have enough juice.. but that’s being critical. ;)