What cert next?

So I was just awarded my ISSAP. I have the other concentrations, too. With the new flat AMFs for ISC2, I was considering just... Studying and taking all the rest of their certs for CPEs.

Which ones are the hardest? CSSLP? CCSP? The healthcare one? Which ones are the most relevant to your job (I'm in consulting so they're pretty much equal in my book)?