Tulipa humilis 'Odalisque' when closed...
Tall blue squill + golden acorus = yummy
(Proof that I have good ideas once in a while)
leucojum aestivum 'gravetye giant'
Arabis alp. caucasia 'Snowball'
Dwarf willow: salix yezoalpina
And what spring post would be complete without a little forsythia? And I do mean little (it's a dwarf). A little is enough when it comes to forsythia.