What’s the best broker for a beginner who intends to invest long term in the US market?

Good thing to have a strategy to not do active stock picking.

The answer to Your question depends a lot on the stock exchanges where You want have access to.

Also: currently (compared to 10 years before) are already generally very, very low with all mainstream online dicsount brokers (and will everywhere drop further peu à peu; maybe even so that You will get paid for buying stocks, f.ex. by rebates or blended in advertisements ...)

Yes, TD Ameritrade U.S. branch is super, maybe only possible for Singapore citizen to open up Singapore branch account with (them?), many here write that it takes weeks/months with them to account opening after application.

They will anyway merge with Charles Schwab, expect to know more on the details in 2021, U.S. autorities already approved of the TDA/Charles Schwab merger. Possibly for non-U.S. citizens Charles Schwab will open up accounts only with their U.K. branch ?

POEMS and FSMOne are acceptable companies fee-wise, Standard Chartered seems also a very good one.

good luck.

If interested in what not to do when investing, I wrote some lines here:

https://seedly.sg/questions/what-is-your-genera...

TD Ameritrade! literally no commissions fee

TD Ameritrade. No comm for stock transactions and no inactivity fees. Only thing is that account opening may take some time now.

Firstrade! Don’t say never jioooo