Certifications are really good if you really want to build a career into middle-management, in-house software development departments a.k.a. mega-corp widget factories; these types highly appreciate certificates. A big pharmaceutical company would love to see a Microsoft Certificate over a Github profile since they don't care about the code, they just care about you passing a "industry standard test" so that you would fit X number of requirements and feel safe that they got the right person. Couple your certificate with a filled out LinkedIn profile; and they'll highly consider you.
Building a good Github profile/portfolio website is the better route if you want to build your career around working for companies that sell software as their core product, or well-known shops (Fog Creek, 37 signals, etc.). These type of companies highly value code and work output, and they'd understand the value in your profile. Don't get me wrong, a certificate would help in some way but if you can't show them you can code or be comfortable with the command line, they'll go for anyone else who has built something and deployed it.
If you're going for the certifications route, it depends on what stack you're going for:
For anything with Spring, go through springsource.com/training you'll find some links there for certification classes.
For anything .NET or Windows, go through microsoft.com/learning for more info.
Don't underestimate the amount of time and money spent on studying/getting a certification. If you already have a job, don't take a certification unless you really plan on moving up some sort of mega-corp corporate ladder or if you're targeting for another job that requires a certain certification. The better way to be better that has no strict commitments is to find yourself a user-group of your stack, work with a friend on a project you think is 'cool', or work on some open-source project.
The best thing you can do is build stuff and show it off on a portfolio website or a github profile.
http://education.oracle.com/pls/web_prod-plq-dad/db_pages.ge...
But if you already have a job, you don't need one. They might help you land a job if you don't have a CS degree. Also agree with the other comment: if you are doing JS, etc. then get active in GitHub.