All the potential argument essay prompts are available on the GRE website for you to practice with. There are way too many to even think about writing an essay for each one and memorizing them all, but the list does give you unlimited practice material, and that always helps on a test like the GRE!
During the AWA section of the GMAT, the testing system will randomly select and will present to you one essay topic (prompt) from a large pool of more than 150 Analysis-of-an-Argument essay prompts.
You can find official Argument essay prompts here.
The GRE Analytical Writing course offers intensive practice in interpreting, planning, and developing both the Issue and Argument essay prompts. Learn how to manage your writing time to reduce stress and produce a high-quality essay.