^^
I'd recommend that you get neither of them and go for a Sony MDR-V6... If you want good quality and clear sounds go for a MDR-V6 because its the best bang for your buck in the <$100 price range.
The Sennheiser HD 218 & Sennheiser HD 228 don't even compare with the MDR-V6 maybe, just maybe the HD 280, but its only good for isolation and that's it. Sound quality is certainly not up to par with Sony.
Don't take my word for it go on
http://www.head-fi.org and check out reviews and ask questions people on there have alot more experience in headphones =D