I'd actually thought about recommending this test on Lesswrong before. I don't know if the Five Love Languages accurately presents any theoretical/neurological underpinnings, but descriptively, it seems very accurate, at least for me.

(I'm the opposite of Omid -- physical touch and quality time together are very important to me; words of affirmation are a little important; but receiving acts of service or gifts does nothing for me, even though I enjoy performing acts of service/giving gifts to my SO) .