i bought koss ksc-75 and senn hd201 last yr from amazon.com
both are really good...but the koss is more livelier and has more bass. Only con is that its a bit uncomfortable if u were it for hours at end.
Im starting to like my senn hd201 more nowadays.
If u cant get both atleast go for ksc-75, u simply cant go wrong with the value for money it offers.
Im no audiophile and moreover i havent tried the grado series, So cant comment on them.
ksc-75 is a must have. wheter to go for hd201 or grado... try asking in
www.head-fi.org you'll find more replies and more info there.