Saxifrages for Spring! the Kabschia (and related) groups are the earliest and toughest bloomers
Moving outside the crocus-daffodil-muscari box for a moment, I'm advocating for early blooming Saxifrages. They are connoisseur plants, giving of themselves for our garden's enjoyment at a much higher level. In return they require only that we follow a few guidelines to get the best out of them.