I've flown with:
KL (lots and lots and lots and lots)
AF (lots and lots)
AZ (a few s/h)
OK (one very short r/t: MUC-PRG)
KE (one 4-seg l/h r/t: LHR-ICN-MEL)
DL (a few, some US, some TATL)
AM (only domestics)
UX (a few domestics plus MAD-RAK x2)
And with the following who are, in one way or another, no longer with us:
NW (they were nice, weren't they)
CO (lots, up until just before they left; I miss their Micronesia routes)
-- Henry