I can't think of a more stereotypical noob statement than this...

You really need to be more specific and do some research. There are major differences between Amex cards offering MR, SPG, Skymiles, Hhonors, etc.

And don't simply focus on the "biggest sign up bonus" you can get. Hint: 50,000 Hhonors points are worth substantially less than 25,000 Starpoints.