The one you can code yourself, one classic mistake I see newbies making is that they think of bots as money printing machines, they think they can just turn on the bot and make profits, when the truth is that if you do not know anything about trading then the bot is useless to you, the best option is to learn how to trade on your own and then once you have been successful for a time then you can code your bot to implement exactly the strategy that you are using in the markets.