Sjoerd

Ok this is fun:

Grand total: 58 airlines

North America: (6)

Air Canada
Canadian Pacific
Wardair
United
Delta
Southwest

South America: (4)

Avianca
Aerolineas Argentinas
Pluna
Varig

Europe: (22)

SAS
Lufthansa
Eurowings
Air Berlin
KLM
Transavia
Martinair
Air Holland
Air France
Iberia
Alitalia
Montenegro Airlines
Swissair
Austrian Airlines
Luxair
British Airways
British Midland
Easyjet
Istanbul Airlines
Turkish Airlines
LOT
Aeroflot

Africa: (2)

South African
Ethiopian

Asia: (23)

Air India
Indian Airlines
BIMAN Bangladesh
Air Lanka
Thai
Bangkok Air
Thai Air Asia
Air Mandalay
Burma Airways
Malaysia
Air Asia
Singapore
Silkair
Garuda
Merpati
Sea Air (Philippines)
Cathay Pacific
Air China
China Airlines
EVA
Vietnam Airlines
Mongolian Airlines
Korean

Australia: (1)

Qantas

brewgator

Let's see - domestic (US)

Delta
Song
United
US Airways
Northwestern
American
Continental
Southwest
People's Express*
National*
Pan Am*
Eastern*
TWA*

Outside US -

SAS
Virgin Atlantic
British Airways
Air France
Austrian
BWIA
Lufthansa

*Defunct. List does not include regional affiliates auch as ASA, American Eagle, etc. I guess I am at 20 and counting. The funniest story is that when I flew BWIA (British West Indies Airways) our guide in Trinidad said it stood for 'Big Wait In Airport' or 'But Will It Arrive'

BBT in NY

Northwest
Continental
Delta
KLM
SN Airlines
Iberia
British Airways
Virgin Express
Virgin Atlantic
China Airlines
Eva Air
Uni Air
Far Eastern airlines
Cathay Pacific
Mandarin Air
Air Canada
VLM
Lufthansa

Eastern airlines*
Sabena*
TWA*
Panam*

MelP

Hmm, let's see if I can remember...

Eastern
PeoplExpress
Pan Am
TWA
American
American Eagle
United
US Air
Continental
Northwest
America West
Spirit
ATA
jetBlue
Cathay Pacific
Virgin Atlantic
British Midland
Aer Lingus
Southern Winds

19...more than I thought! Not bad, considering I don't fly nearly as much as many on this board, and I fly mostly American for the miles. Never flown Delta or Southwest, believe it or not. Of course, the first four airlines are defunct and the last is a mere wisp of what it was when I flew them less than 18 months ago...

caltraveler

American
American Eagle
America West
Alaska
Air Cal
Air Canada
ATA
AirTran
United
Delta
Southwest
TWA
Hawaiian
Braniff
Piedmont
Frontier
Aloha
Jet Blue
Northwest
US Air
Varig
Tower
Eastern
Western
Pan AM
Continental
Aeroflot
SAS
Lufthansa
KLM
Air France
Iberia
Alitalia
Swissair
Olympic
Aeromexico
British Airways
LOT
Virgin
Korean
China Southern
China Eastern
Xiamen Airlines
Brunei Air
Thai
Malaysia
Gulf Air
Singapore
Garuda
Merpati
Simpati
Cathay Pacific
Air China
China Airlines
EVA
Qantas
JAL

57...quite surprising

flytor

Air Asia
Air Canada
Air China
American Airlines
Bangkok Air
British Airways
British Midland
Canadian Airlines International
China Eastern Airlines
China Southern Airlines
China United Airlines
Continental
Dragon Air
Gulf Air
Icelandair
Jet Star Asia
KLM
Northwest
Singapore Airlines
Southwest
Thai Airways International
United Airlines
US Airways

nako

Relatively few, comparatively speaking:

Air Cal
Air Canada (including Air BC and Air Ontario)
Alaska (including Horizon)
American (including American Eagle)
America West
British Airways
Delta
Mexicana
Northwest
PSA
Reno Air
Southwest
United (including Skywest)

Mike

wundagirl1

United Airlines
Lufthansa
Northwest
ATA
AirTran
British Airways
SwissAir
NigerianAirways
British Caledonia
KLM
Air France
Southwest
Suncountry
SwissAir
Virgin
BMI

goingsomewhere

My short list:

Reno Air
Alaska
United
Singapore
Southwest

MilesDependent

Total of 60 airlines and 314 flights...

Adam Air
Air Andaman
Air Asia
Air Canada x 3
Air China
Air New Zealand x 2
Air Nugini
Air Nova
Air Tahiti
American Airlines x 2
Ansett Australia x 12
Australian Airlines (AO)
Australian Airlines (TN) x 2
Bangkok Airways
British Airways
Canadian Pacific
China Eastern
China Northwest
China Yunnan x 2
Compass
Continental
Continental Express
Delta x 4
Delta Connection x 2
Dragonair x 2
Emirates
Ethiopian Airlines
Garuda Indonesia x 2
Hooters Air
Japan Airlines
Jet Airways (India) x 39
JetBlue
Jetstar x 5
Jetstar Asia
Lauda x 4
Lufthansa x 4
Malaysia Airlines x 4
Northwest x 2
Orient Thai Airlines x 2
Qantas x 72
QantasLink x 9
Qatar Airways
Regional Express (REX)
Sahara Airlines India
Silk Air
Singapore Airlines x 49
Southwest Airlines
Swiss International Airlines x 2
Thai Airways x 25
Thai Sky Airlines x 2
Tiger Airways
Trans Australia Airlines (TAA)
United Airlines x 24
United Express
Vietnam Airlines x 2
Virgin Blue x 4
Yanda Airlines
Yemenia Yemen Airlines

1kgirl

Aer Lingus
Aeroflot
Air Canada
Air China
Air New Zealand
American
BMI
China Air
China Southern
Continental
Delta
Dragon Air
Eastern Airlines
JAL
LOT
Lufthansa
KLM
Northwest
Piedmont
SAS & Braathens
Sichuan Airline
Singapore Air
Thai Airways
United
USAir
UTAir

I flew a lot as a kid, but I don't remember most of those (except for Piedmont - I loved the nuts there - I don't know why I remember that -

Other than that, it seems that it should be more than that...

the_traveler

Aer Lingus
Allegany (sp?)
Alaska
America West
American
Brannif
Business Express
Continental
Delta
Eastern
Mall Airways
Mohawk
Frontier
National (the one in the 60's and 70's)
Northwest
Pan American (the original)
PeopleExpress
Piedmont
PSA (back when it was separate)
Southwest
Ted
TWA
United
US Airways / USAir
World

Only 25 different carrriers that I can think of. (Plus many of the "Express"es.)

Mateo4321

Alaska
American
America West
ATA
Delta
Jetblue
Northwest
US Airways
United
Southwest

Alitalia
Iberia
(Soon KLM to ZRH, thank you flyertalk )

Never been on Continental....

gabes80

Aer Lingus
Air Asia
Air Deccan
Air France
Air New Zealand
Air Pacific
Ansett Australia (RIP )
Bangkok Airways
BMI
Cathay Pacific
China Airlines
China Eastern
Easyjet
JAL
Jetstar
Lufthansa
Malaysia Airlines
Qantas (+/- u) & Qantaslink
Singapore Airlines
Sri Lankan Airlines
Thai Airways
Virgin Blue

22 (all for leisure, except for QFlink... ) and some domestic Taiwanese airline as a kid... I knew it was a 727 with OJ as inflight drink!

tcswede

Most likely not all - but what I can remember:
1 A N A
2 Aero Mexico
3 Air Berlin
4 Air canada
5 Air Fiji
6 Air France
7 Air India
8 Air Jamaica
9 Air Lanka = Sri Lankan
10 Air Mike
11 Air New Zealand
12 Alaska
13 Alitalia
14 Aloha
15 American Airlines
16 Asiana
17 Austrian
18 Bangkok Airways
19 Britisch Airways
20 Britisch Midland
21 Cathay Pacific
22 China Eastern
23 Condor
24 Continental
25 Crossair
26 Delta
27 Dragon Air
28 Emirates
29 Finnair
30 Gulf Air
31 Hapag Loyd
32 Hawaiian
33 Iberia
34 Japan Airlines
35 JetStar
36 KLM
37 Korean
38 LOT Poland
39 Lufthansa
40 Maersk
41 Malaysian
42 Mexicana
43 Northwest
44 Olympic
45 Palistan International
46 PanAm
47 Qantas
48 Qatar Airways
49 Sabena
50 SAS
51 Silk Airlines
52 Singapore Airlines
53 South African
54 South West
55 Swiss
56 Swissair
57 Taca
58 Thai Airways
59 United Airlines
60 US Airways
61 Varig
62 Virgin
63 Virgin Blue

I left out the various subsidaries such as for LH Eurowings, Cimber Air, Augsburg Airways etc - vice versa for some of the US carriers.

And again there are still many to try

Cheers

Thomas