The only two that I consistently carry are an Alox SAK Classic SD on my keychain and a SAK Super Tinker.
I always have a larger locking folder I carry for work, and I rotate randomly between a few knives (RAT 1, Flash II, M21, Endura, CB Leek). I just reach into the nightstand in the morning, and whatever comes out first is what I carry for the day. The CB Leek is relatively new, so I've been mostly carrying that for the past 3-4 weeks to break it in (and try out the CPM-D2).
Outside of work, I rotate randomly between a couple of smaller folders (Delica, Flash I, Chive). Same selection method as above.
I have a couple of specific-purpose knives that I keep around regularly, but I don't really ever carry them on me outside of their specific use. Those are a couple of Opinels for food (cleaned and lubed up with non-toxic cleaners and oil) and a Dozier Folder in my work bag (beater and for lending to others that might otherwise mistreat blades).