Bonuses come and go so if you are only after the best bonuses you should check the current bonus offers on those sites. It is never a bad thing to also read the actual bonus terms so you'll know what to expect.
I don't know the Americas Cardroom,so I have no opinion on that. I know GG poker, I think it has great bonuses, Daily Freebie promotion is great for beginners.
Of course, the decision is yours