Well since I became a bit of a MP3 player geek, I upgraded a few parts of my rig over the past months.
My everyday rig is a Sony A729 with Sennheiser CX500s. Everything was dirt cheap even though it's a premium player (got it on clearance for 70 pounds instead of 200 pounds!). 16GB of pure tonal goodness, the combo sounds great.
In a seperate backup box I have a Sansa Clip + with additional 4GB Micro SD for a total of 8GB of storage, along with some Klipsch S4s. The S4s sound a bit better than the 500s (clearer, more natural while the 500s have a bit of a forceful bass) but they fit me less well so it's back to the Sennheisers for everyday use.
I also have a spare Sansa Clip (8GB).
For my full size headphones I use a pair of Sennheisers HD202s which are HORRIBLE and some Koss Pro3AA which are actually pretty good and clear, but with a bit of a mid slump.
My dream portables right now are either Sennheisers HD25-II or AKG K181 or K518 (probably the ones I'll go for).
My dream full sizes are some Audio Technica AT-MH50s. They're easily driven so I could even use them with my players and they're great for monitoring.
So get your geek out and show your rig.