Measure leaf size and count veins and flower details etc... that helps alot -- then you can go to the hosta Library database (
http://www.hostalibrary.org or www.myhosta.net) and look up to see if the suggestions match what you see. It's tough sometimes with the more common looking one's but this one is a bit more unique!!
Anyways -- my first thought was Fragrant Bouquet but I think that only has 7 veins... my better guess is Sweet Innocence (It was introduced in 2004 i think)
Happy hunting!!!