Addressing STDs

My Sunday night project (in addition to consoling FH through the Giants' loss) is addressing my STDs. I know these don't need to be as formal as the invites, so I'm having trouble figuring out how to address one to a married couple. What did you all do? Here are the options I've come up with and I don't know which way to go (Feel free to provide another option ):

1) Mr. and Mrs. John Smith (I've heard I shouldn't use the amperstand (&) in addresses?)

2) Mr. John and Mrs. Jane Smith

3) Mr. John Smith
Mrs. Jane Smith

our side of the family and friends we did:

Joe and Jane Smith

for DH's side (friends of his parents) we did:

Mr. and Mrs. Smith

My MIL addressed the cards as
Mr and Mrs L Smith

or Ms Jessica Doe


We went formal even though they dont have to be