The Kiwi, by a mile. I've carried one in my watch pocket nearly every day for the past 17 years. Own a slew of them, both production and custom but these are a few of my favorites (some appear in more than one photo)...
L-R: All stainless - engraved by Marcus Hunt, SFSW custom in Sambar Stag - engraved by David Clevinger, all stainless - engraved by Antonio Montejeno
Top row L-R: Waterfall Oak, end grain Red Palm, Curly Koa, Ebony
Bottom row L-R: SFSW "Earthling" marquetry, Birdseye Maple, SFSW "Wooden Eagle" marquetry, Lignum Vitae, SFSW "Tequila Sunrise" marquetry
Top row L-R: Abalone, Ivory, Birdseye Maple, Jigged Bone with FFG by Tom Krein, Sun Yellow Corian
Bottom row L-R: Tortoise Shell Acrylic, Buffalo Horn, Sambar Stag, Mammoth Ivory, White Pearl