All good suggestions. I have a Gerber Para, just like you posted and love it. I also have shrades, case, spyderco and even a Harley Davidson knife (I love it but it leaks oil in my pocket). One thing I am never without is my Swiss Army Knife, a Victorinox, to be specific. They are inexpensive, reliable, easy to sharpen and very low maintenance. I've used mine in places you would probably never believe.
I also have to mention the Swedish Mora blades. They are awesome if you want something in a sheath. I buy the naked blades for about $7 and make handles and sheaths for them out of pieces of wood I have laying around. Ben's Backwoods is a reliable place for those.