Hmm, interesting... Let me see.

UK: LCY, LHR, LGW, NWI
FR: CDG, ORY
NL: AMS
NO: OSL
CH: ZRH, BRN
CZ: PRG
RO: OTP
HU: BUD
US: LAX, SFO, IAD, ORD, DFW
MX: MEX
HK: HKG
PH: MNL, CEB, TAG
TH: BKK
IT: MXP
PT: LIS
DK: CPH

Uuhm...25. :)

MAD
BCN
AGP

VCE
ATH
CDG
LHR
DUB
VIE
SZG
HEL
AMS

JFK
MIA
ORD
IND
MEX
SJO
PTY

HKG
BKK
SIN

SYD
MEL
NAN

Ahh...time to see what kind of a year it's been again :)
More interesting to see what airports are tops in number of times passed through, to me, actually...

Domestic US:
ORD 22
MKE 14
MSP 6
IAD 6
LAX 5
SFO 4
SEA 3
RDU 2
LAS 2
MDT 2
DEN 2
HNL 2
LGA 2
LEB 2
LGA 1
EWR 1
DFW 1
MCI 1
ANC 1
PDX 1
CMH 1
CLT 1
SRQ 1
TPA 1
MCO 1
BWI 1
SNA 1
JFK 1

International:
SIN 25 ( ^ )
CDG 12 ( :td: )
HKG 8
BKK 7
NRT 7
LHR 5
DXB 5
KUL 3
JHB 2
KCH 2
CMB 2
MRU 2
FRA 2
DUB 2
AMS 2
ICN 1

46, plus DPS, PIT, PHL, HKT and one other, all booked or in process and not yet flown. That's a different airport every week :(

Not that long a list in my case (19 airports), but it's they year I've flown the most, so I'm quite proud of it, and I hope it's longer next year:

Spain: BCN (Base), SVQ
France: CDG
Finland: HEL
Austria: VIE
Romania: BBU
India: BOM, IXU, PNQ
Singapore: SIN
Hong Kong: HKG
Mainland China: PVG, SHA, NGB, FOC, XMN, CAN, PEK
Thailand: BKK

By the way, can you point me out to a website where I can check all airport codes at a glance?

Thanx!