knives you HAVE to own?

[timberweasel]

My 'must haves' include: small keychain SAK (I prefer the Victorinox Rambler), regular SAK (I like 'double-stack' Vics: any thicker and I won't carry it very often), a traditional style slippie, modern one-hander, a 'gentleman' folder of some kind, and an outdoorsy fixed blade.

Pretty vague, I know, but what can I say? I'm a fickle knife-guy and my preferences are wont to change without notice...