My everyday knife I carry is a Gerber Freeman folder. It rides on my belt, and it's with me 24/7. I also carry a small Gerber folder as a utility knife for doing rough work. It lives in my pocket. Both of these knives never stay home unless I'm attending a formal event where a belt or dress pants doesn't really permit. When that's the case, I have a very thin Winchester folder to go in my pocket. (It was even there on my Wedding day)
If all else fails, I have a Victorinox Swiss Army style knife on my keys. Sometimes it's handy to have. Besides the Freeman, if I'm going fishing, I wear a Russel filet knife on my belt. If I'm hunting in crappy weather or rough country, my Buck folder in a leather sheath is on my belt. If it's cold outside, I have a Gerber Gator in a ballistc nylon sheath on my belt. If I'm camping, or just going for a hike in the mountans, I have one of those big Buck knives on my belt, usually with a Gerber Gator folding saw.