Suggestions from Redbrick people about headphones
Replacement earplugs for iPod/iRiver type devices
Doc: I like My Sennheiser MX400s. Got them in HMV, if I recall. They're not green, though.
Bubble: Sennheiser MX400 / MX450 if you're on a budget, but they don't last a particulary long time with heavy use. Etymotic ER6 are excellent. They go well into your ear, so take a bit of getting used to, but are worth every cent (Also do a search for ER6 vs ER6i, both are good, but have subtle differences, small mp3 player users go for the ER6i).
Marvin: Sony Fontopia earplugs. 50 euro from the Sony Centre but worth every cent.
Jammy: Etymotic ER 6 or ER4s. No doubt Koss portapro (they hook on your ears)
Czarak: Etymotic ER6i
Pixies: Sennheiser PX100
Seamusmc: Shure E2c
gizmo: Etymotic ER 6i Black. €78 from Expansys, pricey but fantastic
Big headphones that won't fit into your pocket
Dizer: Sennheiser 580 Sennheiser 280
Bubble: Sennheiser PX100 - excellent, comfortable, and reasonably priced, but leak a lot of sound to those around you (and come with a sturdy carrying case).
Jammy: Senn 280 pro Sony 7516 Ultrasone 650
Czarak: Sennheiser HD 25-1 II
Homerj: Beyerdynamic DT250s Sennheiser HD595
Kane: Sony 7506s, senn 280 pros or k271
Calyx: Sennheiser PMX40s, small-ish on-ear wrap arounds - about e35 - really great sound though
phaxx: Bose Around-ear headphones. ("Triport") - Around 150 euro, but very comfortable.
gizmo: Audio-Technica ATH-A900. $180 from Audiocubes. Closed back, fantastic sound and build quality.
druid: Sennheiser HD 595 & Beyerdynamic DT 880s. Much prefer the Senn.
Shops that sell headphones online
http://www.audiocubes.com (Japanese site but with super fast shipping and fantastic prices)
http://www.discountheadphones.com/ (Not exactly the cheapest prices for the headphones themselves, but with free (and quick) worldwide shipping, they're a cheap spot to get replacement parts - e.g. filters for etymotic ER6/ER6is).