What are the best knife options for your keychain?

I ponder the question of best keychain knife, from Al Mar to W.E.S.N.
Featured in this video:

Cold Steel Recon 1 Micro
Cutco 1886
WESN Microblade
Spyderco Ladybug
Spyderco Manbug
Spyderco Roadie
Spyderco Cricket
Al Mar Stinger
Case Caliber
Gerber US1
Gerber Key Note
Schrade+ USA SP2
SOG Centi
Victorinox Classic
Kershaw Chive
Kershaw Cinder
Kershaw Grant Country
CRKT 6400 Angus
And many more!