What is the best visa option for staying in Thailand for 6 months or more?

I thought they were not offering Multiple Entry visa, for American passport holders (maybe everybody).

Multple-entry are good for 60+30 days for each entry. You will be required to leave the country every 90 days. The last time I used METV I would go to either Cambodia or Myanmar, exit Thailand, give my passport to someone hanging around, an hour later they would show up with my passport stamped in/out of the next country. I didn't have to enter another country, only exit Thailand.

The entry/visa requirements here in Thailand are fluid. What is your best option today may not be the best option. Depending on your schedule you may want to

A) Come and see what is available after 90 days (end of your first visa)

B) wait until after July (or May) and see what options are available to you.

Longest time possible would be the Elite 20 year option. If money isn’t an object.

Failing that you could do a STV (special tourist visa) that gives you 90 days and is extendable twice for a total of 270 days. But it has a bunch of requirements that a normal tourist wouldn’t want to meet.

A multiple entry tourist visa is valid for 6 months and on each entry you get 60 days. If the entry requirements reduce as expected in May this may be an option for you.

Alternatively you can enter on a tourist visa, or exempt and explore options for an in country extension.

For what purpose?