Pretty much any (major) character designed by bones passes the silhouette test. Out of Bebop, Champloo, and Dandy I think Space Dandy has the best character designs. Spike silhouetted next to Mugen and you can tell who is who. Faye next to Honey next to Scarlet next to Fuu and you can tell who is who. Everyone has designs that serve the universe they inhabit and you can make some very easy assumptions about their personalities from just looking at character sheets.
What makes a good design isn't necessarily recognizability; Kirito, for instance, has a generic as fuck design, even despite being relatively well recognized. A good design tells you exactly what you need to know about a character from a single look. A great design isn't boggled down by too much (unnecessary) detail. And the best designs are recognizable even when looking at the silhouette of a character.