The best taxi company by far, Blue Bird Taxi uses blue vehicles with a light on the roof bearing a stylised bluebird. Drivers speak reasonable English and use the meter at all times. Many expats will use no other firm. Blue Bird has a slick app that summons a taxi to your location just like Uber.
Watch out for myriad fakes – there are many. Look for 'Blue Bird' over the windscreen and the phone number.