Also look at Gerber and Leatherman. Bear in mind you can't carry a lock knife in public. I have and like my victorinox, but as I don't use many of the tools, so just have a large blade and corkscrew basically.
EDIT - I have
Victorinox Nomad
I also have
Gerber Suspension
Glock FM81
The Gerber's blade is too short, so I mainly use the pliers. Handy if I only want to carry one tool and don't anticipate using it, such as hiking.
The Victorinox is my "main" knife for camping etc.
The Glock is handy for splitting wood and levering things open
If you want something for just in case, get a basic, non locking Victorinox or the Gerber Suspension. If you want a knife, maybe look at the Mora sheath knives? If you want a multitool, Leatherman are good if you spend a bit more money (the cheap ones aren't much good IMO).
Bear in mind Leatherman and Gerber both lock, so you can't carry them "in case". Same goes for sheath knives. A non locking, sub 3" Victorinox would be fine in a car glove box etc.
Get a knife with what you need - its a very personal thing. I use each of mine for different purposes, but it's suprising how little you use some elements.
