I've always used what I've had, and done things by intuition. That was whittling when I was a wee lad, and I'm just an overgrown version of that now...
My Opinel 8 is the one I use most. I think everyone should have one. Nicely made knives, functional, cheap. My dad gave me mine when I was 12 or so, and I'd be happy doing the same. My first 'proper' knife was an SAK Spartan, and I'm fond of them, but the Opinel is more functional as a knife, in my humble opinion. I've also found the blade shape useful - I like having the upswept portion (whatever the proper name for it is
) to choke up on the blade and use for controlled chisel-like cuts, for example.
That said though, it's not without its drawbacks. The points on them are very flimsy and the locking mechanism is pretty feeble (yet still UK illegal as far as I'm aware?); I've had it fold on my fingers many a time and have worn the plasters to prove it.
I think the Mora 106 is a better knife for purpose and I intend to pick one up at some point, but no knife collection is complete without at least one Opinel. A classic.