This could be somewhat of a controversial post. It deals with certification and braindumps and "cheating". You have been warned. :)
First off, I hold several Microsoft certifications. Second, I have seen some of the offerings of TestKing, Pass4Sure, ActualTests, and RealExams for myself. There are dozens of others, I'm sure, but quite frankly I don't have the time nor the desire to search them out. That's what http://www.certguard.com/ is for.
The observations in this post are strictly my own, and are based on my perusal of some of the aforementioned braindumps, which is the basis for my opinion, and thus this blog entry. If you stumbled across this blog entry as a result of searching for such materials, you won't find any here, but I would ask that you read the entire post before continuing on in your search.
A braindump, such as one listed above, is cheating. Nothing more, nothing less. Knowing the answers to an exam before taking it cannot be called anything less.
You cannot, I repeat, CANNOT, justify the use of braindumps to me. Don't even waste the energy even thinking about trying to justify it to me. If you know the questions before you take test, and can do a decent job of memorizing the answers, what have you learned? How to memorize answers, that's it. You haven't learned the material, you haven't spent hours and hours in some kind of lab environment learning about the product, how it works, how to configure it, what x and y and z can do.
What can or should you do? This is simply my opinion, take it with as many grains of salt as you like. Turn in cheaters. If you see people asking for braindump materials, get their name and/or e-mail address, plus the site where you saw the post, and report them to the appropriate certification source (Microsoft, Cisco, Red Hat, etc.). It may not be the same e-mail address they have on file somewhere for their certification, it could be (and probably is) a fake name, but at least you're alerting companies to the cheaters and where they like to lurk. If companies like Microsoft can take down these braindump sites, it raises the value of their certifications because there is no more "easy" avenue. Granted, if someone wants to cheat, they'll find a way. And taking these sites down will simply push them into the deep, dark corners of the interwebs. But that's fine with me.
In the end, if you use TestKing, ActualTests, et al., as your "prep" material prior to an exam, then your certification is worth exactly what you paid for those materials. You've learned nothing of value, and in any real world environment you will be exposed as a fraud, if you even make it past a good interviewer. You have nothing to be proud of, no reason to show off the letters you can put behind your name. For those who do not go that route, and learned on the job, in a lab, while pouring hours and hours of their own time and hundreds, if not thousands, of their own dollars into lab equipment, books, software, etc., your certification is priceless. You can be proud of your achievement.
In the end, I'd rather have something I can hang my hat on and be proud of than have something that I don't deserve.