I like this one in green:
http://www.jcrew.com/catalog/product...atId=cat120158
this one in red:
http://www.jcrew.com/catalog/product...atId=cat120160
or this one in coal
http://www.jcrew.com/catalog/product...atId=cat120160
They're nice enough that you won't look underdressed, but not so nice that you'll look like you're going to your Senior Prom if everyone else is in suits or plain skirts/tops.
I am too lazy to do anything more than post the links. Sorry
