The Romantic - 10
Take a villager on a perfect date, or tag along to one. Location and expressions are all-important.
Location and expressions indeed. Simply target (left trigger) and press Y to find out their perfect spot, perfect expression or perfect gift. Some show them, some don't, so find someone that shows the place and expression. Then, get them to follow you there; it might take a bit of groundwork to get them there and be careful of the sexes issue (women might not like women), but once there, perform the perfect expression (see The Show Off) and if that doesn't work, give them their perfect gift. I personally got it with just the place and expression.