I named my husband's bikes for him:

The Cannondale (his roadie). I also have a Cannondale but since his took the name I call mine Miranda.

The Stumpy or just Stumpy. His Specialized Stumpjumper FSR.

Jake or The Kona. His Kona Jake Cyclocross bike.

When talking about my bikes to people I call them "my Cannondale", "the Fisher" or "my hardtail". Like they will just follow along with that.