What are the best visa options for staying in Thailand for an extended period during Covid?

I think your best bet to maximize your time is to come on a tourist visa (60 days), then get the extension (30 days). Within these 90 days you can consider your other options. Most popular is likely to be the Education visa and enroll at a Thai language school. You can search around and find a reputable one that requires attendance and concerted effort, and you will learn Thai. There are also some less reputable options that will gladly take your money for classes but not require much else from you.

This can buy you around another year in the country.

You also have the option of trying to milk Covid extensions if they keep that program going, but it's risky because they only keep that program running 2 months at a time, and only announce if it will continue a day before it expires. Also immigration officers have been getting a little more strict on asking about why you can't return to your home country and need to stay in Thailand. But there's very little effort required on your part besides going to immigration every 60 days.

Theoretically you could use Covid extensions until they stop that program and then switch to Education visa, but normally you cannot convert to ED visa within the country and they've only allowed that while the borders are closed, so if they end the Covid extensions it's possible they end the ability to convert to education Visa inside the country as well.

@Chad *********

And how long is "more then 3 months", and for what reason? You can get an elite visa for 20 years