I only have one at the moment, a Wenger Handyman, but it has done everything I have ever asked of it, which is an awful lot. From whittling to cutting PVC pipe and 1x4"s with ease, to unscrewing my niece or nephew's latest toy's battery compartment to add batteries, to putting new holes in a too-large leather belt with the awl, to removing splinters with the tweezers, to opening cans at the campsite, to opening my Dad's bottled beer or my Coke, to filing my fingernails. I love it. Plus, it has sentimental value to me, being my first knife.
I've got my eye on a Victorinox One Handed Trekker, too. It seems like a really handy knife as well.