Nigeria and Cameroon are probably the worst. That green Nigerian jersey; what is that colour?
Croatia's jersey is messed up, especially with that huge white block for the number. Don't like it.
JureM is right, blame Nike.
Brazil usually has classic jerseys, but Nike designed some bad jerseys for Portugal, Brazil, and I think the US?
Those 3 have too many lines running all over the uni. Under the number, up the sides to the armpit, across the shrts, across the socks, etc...
I'm also not impressed by the pecs on the Italian players. Those jerseys seem too tight, and they should be darker blue next time.