Froggy Went A-Courting/ The Frog and the Mouse is a good example. Lots of versions on both sides. (I'll leave it to you to do the choosing.)

Last fall the fifth grade at my local elementary school was lucky enough to be visited by Mike Seeger, then a few months later, Englishman John Roberts (I confess, it was all my fault). Mike Seeger did "Johnson Jinkson", and John Roberts did the "Three Butchers". Mike's Johnson Jinkson is from the Todd & Sonkin Migrant Worker Collection at the Library of Congress (go to this site, browse by "song titles" and look for "Johnson Jinkson"). John Roberts does the Three Butchers on "A Present from the Gentlemen" (available from Golden Hind Music).

I like to use the Gant family's Texas version of The Nightingale/One Morning in May collected by John Lomax: "The Wild Rippling Water". (The DT version is as adapted by Judy Collins. You can get the original from Alan Lomax's Folk Songs of North America.) The version the Clancy Brothers sang was actually from Oxfordshire, England.

There are of course LOTS more examples. You could start with any ballad in Cecil Sharp's "English Folk-Songs from the Southern Appalachians". Or browse your way through the Ballad Index.

~ Becky in Tucson