I just added 'Jolly Good Yellow' to my Want List, sounds like my type of plant.
Now to choose just one....well, I just can't decide on one and I have new ones on the way so even if I did choose just one it might change pretty quickly! But I do like ones with large bright blooms that show up from across the garden, have scads of blooms, multiply at a decent pace and have a long blooming season and are very rust resistant! I have a few that almost fill all those criteria, but none of them quite meet the large bloom criteria while having all the other traits, when I find one that has seven or eight inch blooms and all those other listed traits, that will be my one favorite daylily!