What are the best Thai SIM options for long-term expats in Thailand: AIS, True Move H, or DTAC?

I use Saily when I go for a month at a time

AIS

AIS all day long if you’re gonna get a contact.

I prefer AIS, you can pay per year, for unlimited data at a reduced speed.

Ais

Just came back from Thailand a few weeks back, and i very highly recommend Jetpac esim I bought the 10$-50gb pack and the setup was super easy! Took me 4-5 mins. I landed in Thailand, and switched it ON! It took about 1-2 mins to connect! It was amazing 5G and awesome speeds! It was working even on phiphi island! We went to Phuket, Koh samui and Chiang mai/rai. Really amazing and highly recommended! They also have an added perk of free lounge access if flights delayed, though our flight was on time, so we couldn’t use that! Website below Www.jetpacglobal.com

AIS has the best overall network coverage in Thailand..

However Dtac is also very good so either would be fine ..

Check out thier websites

I prefer AIS.

I use AIS when in country for a few months at a time.

If you are going to be in major areas, then AIS is the best. If you are going to be out in rural areas, then you would need to ask people that live there which of the carriers has the best signal.