Get to Chiang mai by Plane or leaving it?

Chiang Mai International Airport (CNX) handles both domestic and regional international flights. The route from Bangkok is one of the busiest in the country (Thai Airways flies daily almost every hour, with additional flights in the peak tourist season). Other airlines landing in Chiang Mai include:

• Air Asia - from/to Bangkok (Suvarnabhumi airport); also Kuala Lumpur (Malaysia)
• Air Mandalay - from/to Myanmar
• Bangkok Airways - to Ko Samui (flights from Ko Samui are indirect), from/to Bangkok (Suvarnabhumi) and Sukhothai; from/to o Siem Reap [(Cambodia)]
• China Airlines - from/to Taipei, Taiwan 
• Lao Aviation - from/to Laos
• Korean Airlines - from/to Soul, Korea
  
• Nok Air - from/to Bangkok (Don Mueang airport), Mae Hong Son & Udon Thani
• One-Two-Go airlines
  
• SGA - from/to Chiang Rai (once daily) and Pai (once daily)
• Silk Air - from/to Singapore and beyond
• Thai Airways - from/to Bangkok (both airports) and to Phuket and/or Mae Hong Son (as Nok);  in addition, flights  possibly Nan also Kunming (China); may also be available seasonally

The airport is some 3 km south-west of the old walled city, only 10-15 minutes away by car. The official airport Limo (non metered taxi really) charge a flat 120 baht for up to 5 passengers (but seldom fit that), anywhere in the city; if you take a metered taxi, the fee will start from 40 baht + a 50 baht service fee from the Meter Taxi counter. The taxis operate from the exit at the north end of the domestic terminal - after baggage claim and/or customs, walk into the reception hall and turn left and walk into the domestic wing. Alternatively, take bus #4 to the city center for 15 baht, {or charter a tuk-tuk or songthaew for 50-60 baht if one ther but may only pick up if came in with customers}. Most hotels and guesthouses offer cheap or free pick-up/drop-off services so be sure to ask before booking..