I adore the little dwarf bulbous irises -- I. reticulata, various related species and hybrids. They flower super early, mine have been blooming for about a month now, and unlike, say, snowdrops, which one only loves because they are early (I mean, really, if snowdrops bloomed in June, no one would have ever heard of them) these little guys have some of the most incredibly beautiful, intricate, fragrant flowers I know of.
Smudge, our cat, liked it too.
I've heard from other people that dwarf irises sometimes fail to rebloom in subsequent years, but I've never had that be a problem. I think the key is good drainage and full sun while their foliage is up in the spring. But even if they didn't rebloom for me, I wouldn't be without them. They are beautiful, cheap, and easy. What more could you ask for?