This is the kind of question which many publications and some authors (including yours truly) devote considerable time and effort investigating and reporting on. Rather than answer your question directly, I'd urge you to consult Top 10 lists at CertCities.com, annual cert surveys at CertMag.com, and an article on top-earning certifications I've written recently for SearchWinIT.com, "What are you worth? IT Salary Surveys Shed Some light". These will not only help you answer that question for yourself, but will include pointers to other resources you can consult for even more information on this always-interesting topic!
This was first published in March 2006