As the latest movie incarnation of Alexander Dumas' "The Three Musketeers" gets the steampunk treatment, we'll find out why young d'Artagnan wants to hang with this trio … in 3-D no less! But movies have long known the power of a good threesome (not like that), so we're counting down our favorite terrific trios.

As the latest movie incarnation of Alexandre Dumas' "The Three Musketeers" gets the steam-punk treatment, we'll find out why young D'Artagnan wants to hang with this trio … in 3D, no less!

But movies have long known the power of a good threesome (not like that), so we're counting down our favorite terrific trios.