Here's an example of a super polite version: 失礼ですが、(お客様の)お名前は何とおっしゃいますか？ "Shitsurei desu ga, (o-kyaku-sama no) o-namae wa nanto osshai masu ka?"

I don't know, may be exist a "super polite" version of this question, but you may ask this way: あなたのお名前は何ですか。Anata no onamae wa nan desu ka? But I think the best way is to say your name to a partner... Politness will demand from your partner introduse himself too.

you can also say, just like t1n9 mentioned, "namae wa?", which would literally be translated as "what about the name?", given the context it would mainly be directed to a "you", the person you are talking to.

i only learnt "o-namae wa?" heehee =]