Alpari is a large global service provider/ they used to be one of the largest and most known ones but the company has been somewhat in decline, that said they are working their way up again slowly, still, a good broker to trade with, but there are betters

Founded in 2006, AvaTrade has offices in 11 countries and provides multiple trading platforms for web, desktop, and mobile devices, offering spot forex and forex options and CFDs on numerous asset classes, including cryptocurrencies.

XM.com is a large forex broker that has been in business for more than ten years now. they are fully regulated. in general, the reputation is good