I realize what a tiny list I have, but I read all the others in hope that one day mine will be just as impressive.

Domestic

ANC - Anchorage
ATL - Atlanta
BNA - Nashville
CLT - Charlotte
DCA - Washington Reagan
DEN - Denver
DFW - Dallas/Fort Worth
ELP - El Paso
FCA - Kalispell
HVN - New Haven
JAX - Jacksonville
JFK - New York
LAX - Los Angeles
MCO - Orlando
MIA - Miami
MSP - Minneapolis/St Paul
OAK - Oakland
PHL - Philadelphia
PHX - Phoenix
SFO - San Francisco
TPA - Tampa

Domestic: 21

International

AMS - Amsterdam
BLQ - Bologna
CDG - Paris
CMN - Casablanca
CTA - Catania
DUB - Dublin
FCO - Rome
FLR - Florence
LGW - London/Gatwick
LHR - London/Heathrow
MUC - Munich
PMO - Palermo
RAK - Marrakech
SJO - San Jose
VCE - Venice
YYC - Calgary

International: 16

Grand Total: 37

(Most recent airports in italics)