I knew when I stopped I would think of the rest of the nurseries that we regularly order from. By mid morning I had thought of 3 more, so here goes.
Ensata Gardens http://www.ensata.com has a wonderful selection of many types of irises. We have been ordering Japanese/Ensata and Siberians from them and also some species and crosses. Really nice website which was just updated.
Iris City Gardens http://www.iriscitygardens.com is my other favorite iris nursery. I especially like their selection of Louisiana Iris and their older tall bearded cultivars. Newer ones seem to be more susceptible to rot and don't do well here. Greg and Macy's older ones grow like crazy.
Brent and Becky's Bulbs http://www.brentandbeckysbulbs.com If I only had one place to get daffodils and other spring bulbs, this would be the place. Wonderful selection and great prices. Much better bulbs than the cheapy catalogs with the flashy pictures.
If I think of more, I'll be back, but this might just do it for awhile.