It's been a while since I gave a shout out to one of my favorite non-Microsoft certification vendors, Brainbench.
What I like about them, nice looking certificates, online transcript, and FREE test taking. Check out their tests for free!
Here's a few that speak to me:
And here's the whole list:
Now, don't get me wrong, there's a bunch of others that cost money and if you decide to go that route, a subscription is probably the best way to go.
The downside: since the tests are delivered online (which is very convenient!), there's no way to make sure you don't cheat (say by having someone else take the test for you). So, really, these tests are just for you to tell yourself whether or not you know a specific technology (and to what degree).