Two instruments that go perfectly together for just about any style of music.
Brides- and grooms-to-be are often looking for "strings" or "string quartet" or "violin," "cello," etc.
If that's you, then one option to consider is guitar and cello duo. Because the guitar typically plays more than one note at a time, you're getting a somewhat fuller sound than 2 "string" players.
And you can have just about any style of music you want - from classical to pop to tango and everything in between.
Have a listen to some of the samples below.
Of course, if you have your heart set on a string trio or quartet, you should get in touch with the Emperor Quartet -- it's one of the best you'll find.