I've been on kick to find good a capella covers of Beatles songs, and so far I've found these:
Who's Your Daddy! cover of Strawberry Fields. I love the rhythm and I'm really impressed by the "cello" sound.
Swingle Sisters cover of the same. Gorgeous. I kind of wish someone could find a way to mesh the two covers.
The Dolls' cover of Dear Prudence. The lead's slightly flat, but it's a delicate and lovely version.
Still looking, I'll probably update with more.
parlance