That is a tough one since I tend to know the good US/UK brokers however I know of two of the brokers on your list.
FXopen - Never used them, they tend to have mixed reviews but most people say they are good. I know a few traders who use FXOpen and they seem to like it.
TadawulFX - While I cannot recommend it myself as I have never used them. I know quite a few traders who do use them and I have only heard great things about this broker.
Vantage and Gomarkets I do not believe I have ever heard of. You should also check out Ikon-Royal.com they are a good broker.
From the list you gave me I would say TadawulFX is the better broker. Plus they are a Swiss broker so they probably are regulated there which is a good thing. Swiss regulations are tough! You should ask about whether or not they are regulated first.
FXopen - Never used them, they tend to have mixed reviews but most people say they are good. I know a few traders who use FXOpen and they seem to like it.
TadawulFX - While I cannot recommend it myself as I have never used them. I know quite a few traders who do use them and I have only heard great things about this broker.
Vantage and Gomarkets I do not believe I have ever heard of. You should also check out Ikon-Royal.com they are a good broker.
From the list you gave me I would say TadawulFX is the better broker. Plus they are a Swiss broker so they probably are regulated there which is a good thing. Swiss regulations are tough! You should ask about whether or not they are regulated first.