Airlines

I'm pretty sure there are more, but on top of my head, I can only recall using 89 different airlines on my travels. 

• Aegean
• Aeroflot 
• AeroMéxico
• AirAsia
• Air Astana
• Air Baltic  
• Air Botswana
• Air Canada
• Air France
• Alaska Airlines
• AnadoluJet → AJet (same airline, rebrand)
• Avianca 
• Azerbaijan Airlines
• Batu Airlines
• Belavia
• Biman Bangladesh Airlines
• BMI (defunct)
• Boliviana de Aviacion (BOA)
• British Airways
• China Eastern Airlines
• China Southern  Airlines
• Cubana 
• Delta
• Dragonair  (defunct / absorbed into Cathay)
• Easyjet
• Emirates
• Etihad Airways
• Eurowings
• Flyadeal
• FlyArystan
• Flybe (defunct) 
• FlyOne 
• Flynas
• Fuji Dream Airline
• Garuda Indonesia
• GOL Linhas Aéreas Inteligentes
• Gulf Air
• Hainan Airlines
• Iberia
• Iraqi Airways 
• Japan Airlines
• Juneyao Airline
• Kenya Airways
• KLM
• Kulula Air (defunct)
• LAN Chile
• LATAM Airlines 
• Lufthansa
• Luxair
• Malaysia Airlines
• Middle East Airlines (MEA)
• Monarch (defunct)
• Nok Air
• Paranair
• Peach Aviation
• Pegasus Airlines
• PIA
• Pluna (defunct)
• Precision Air 
• Qantas
• Qatar
• Ryanair
• Saudia
• SCAT Airlines
• Shaheen Air (defunct)
• Shanghai Airlines
• Singapore Airlines
• Sky Airline
• Sky Express
• Somon Air
• Southwest
• SunExpress 
• SWISS (Swiss International Air Lines)
• Tap Air Portugal
• Tara Air
• TAROM Airlines
• TezJet
• Thai Lion Air
• Thomas Cook Airlines (defunct)
• Transavia 
• TUI Airways 
• Tunisair
• Turkish Airlines
• Uzbekistan Airways 
• Valuair
• Virgin Atlantic
• Volaris
• Westjet
• Wizz Air 

Airlines on my Bucket List:

United Airlines
JetBlue
EVA Air
Cathay Pacific
LOT Polish Airlines 
ITA Airways
Finnair
Korean Air
Brussels Airlines
All Nippon Airways (ANA)
Scandinavian Airlines (SAS)
STARLUX Airlines 
Asiana Airlines
Air New Zealand