Hi all,
I voted other because my husband and I have confused things more than usual. We got married when we were both 30 and neither one of us really wanted to "give up" our last names. So we compromised and both took on a hyphenated name. We are Mr and Mrs MyLastName-HisLastName (hereafter called Jones-Smith for simplicity). We chose to put my name first because it sounded better than Smith-Jones, and that was, honestly, the only reason.
You can imagine the mail we get

Virtually every permutation under the sun except for the correct ones. I've had my last name changed into a middle initial (Mrs SMuFlo J. Smith), he's received things sent to Mr. Jones, and sometimes I'm not sure how they came up with the combination.
I answer to almost anything at this point, and I only get annoyed in two situations:
1) When certain members of his family INSIST, despite numerous gentle reminders, to send cards, checks, whatever to Mr and Mrs Smith. If only I had hyphenated my name, I'd be fine with that. However, we both have the same last name (albeit a long one), that we like and we'd really appreciate it if they'd use it.
2) When business colleagues or various "professionals" that we encounter on a regular basis (i.e. doctors, insurance agents, etc) call me Mrs Smith, then get upset with me and argue that I'm incorrect when I gently remind them of how I like to be addressed. In the case of the Doctor, our health insurance is under Jones-Smith, and it is important that they get the name right so the claim will go through. The last time I was there, I was subjected to a five minute diatribe from the receptionist about how wrong I was to object to being called Mrs Smith, and that I was insulting my husband and his entire family by "raising a fuss" (which I didn't do, but never mind). I waited until she had run out of steam a bit, and explained that I was not insulting my husband because we were both Jones-Smith. She then muttered something about my husband being a wuss, which I chose to ignore if only to get out of the situation.