Let me see if I can pick a few that no one else has posted.
Alpha Quadrant of Curt Hanson's -- I really like this one for it's relief sculpting. I have grown Supreme Empire since it came out, and have loved it all these years, but Alpha Quadrant shows even more relief than Supreme Empire (SE is one of AQ's parents).
Good old Penny's Worth. I like this one because it is so small, and I can tuck pieces of it in the edge of my perennial beds. It reblooms many times for me, so there are always little yellow blooms here and there. I like planting the Johnny Jump Up Viola's near it because the color of Penny's Worth echoes the yellow in the violas.
Mighty Sol (Dottie Warrell) Another that is on the golden side of yellow - but makes such a great clump. Big spidery thing - one that makes me thankful that I live so close to Dottie! Mine was dug up and divided by a friend 3-4 years ago, and has sulked ever since. I need to have my friend Bob down here to see if the other person planted it to deep or what is going on with it. It is increasing but not blooming well at all - and it did very well before that... something is up with it.
Pee Wee's Big Adventure (Curt Hanson)
I grew this for many years as "OSxSE" - Curt sent it as a bonus plant the year Supreme Empire came out, as it is as seedling of SE. I loved it. It is a bud builder, and I kept telling him to intro it as I often had it blooming until the winter freezes took the scape down. Some of my best seedlings have come from this plant - and definitely my best bud builders. It has a sear-sucker texture, but it is also very thick and waxy at the same time. Sometimes it pinches and pleats, sometimes it's big wide and flat throated. Sometimes the edges are very fringy, sometimes they show teeth. A full sib to Concrete Blonde and Planet Claire.
And, for one last one -- perhaps this one doesn't fit "yellow" - it has golden yellow petals and orange yellow sepals. A seedling of mine, Bill Norris x Planet Claire. I tend to like more tailored daylilies... so this one is right up my alley. Since I pulled it from the seedling bed, I moved it to the back row of one of my main daylily beds, and it is right next to the big cottage garden type perennial bed. It has clumped up nicely, and it always instant reblooms. It's not shown me anything making it worth introducing though. Not that many people like yellow, and tailored daylilies are definitely not "in"....
Some days it shows itself to be more tailored than others. This year, it was more of a full flowered form and less of this open tailored look.
Here you can see my front walk, last year. Right along the walk there is a triple row of daylilies, 25 plants long. To the left of the daylilies, I have always had a handful of shrub roses and a few perennials, but in spring of 2009 a couple friends moved a lot of perennials from a big bed in back of my house so I could turn that bed back to grass. This year, those perennials have really taken off! The seedling above is halfway down the walk, in the row furthest from the walk... you can see it peeking up above a pink daylily.
A week or so later, things were really popping... from the "perennial" side of the bed... you can see the seedling in the background. Can you see what I mean when I say that the yellows (and golds) mix well with mixed perennials?
It was SO hot and SO dry this summer that I took very few photos. The new part of the perennial bed out front is like a jungle now.
it has some weeds in there, but you can hardly see them. I pinched back the bee balm and phlox in May, but they still grew tall and filled in really well. It has been non -stop color since April. My grass is brown, and I have not dead headed so taking any photos now with all the dead daylily scapes thrown in -- yuck. Hope next year will be better.
My absolutely favorite yellow is DOC WEBSTER which is a Charmaine Rich (from Vermont) intro. Big lovely blooms on tall scapes with a really high budcount and lots of branching. I love this daylily. 
