EmpirePoker is one of the easiest by far, and you can use it for 2 bonuses. One code when you sign up, and then another if you use IGMPAY when depositing through IGM-Pay. They have to be separate deposits though so you'll be depositing at least 1000$ for the max.

That is 500 and 500, but you must clear one before you are eligible for the next one.

I'm not sure of the first bonus code.