This is my first and favorite for a reason. The approach they take and the evidence they present are scientific and straightforward. Their primary focus is not on finding spirits it is on finding a normal explanation for the seemingly paranormal. As such they mention personal experiences but not as evidence. When in doubt, they throw it out. If they don't know what it is or can't say for sure if it's paranormal, they say so. And sometimes, they don't find anything. It seems pretty real to me and every once in a while they catch something pretty awesome.
These guys take a completely different approach. They go looking for the paranormal and they usually find it - a lot of it - which I find hard to believe. I also find it hard to believe that on almost every outing they catch at least one EVP where a spirit calls one of them by name (i.e. "gonna get Zak" or "I don't like Aaron"). But, for some reason, I can't stop watching. They sometimes catch some cool stuff but it's mostly about the entertainment for them... and I find myself entertained.
I actually started watching this yesterday. I caught a marathon and watched about 5 episodes. It was enough to spark my interest. These people purport to be "researchers" but they take a completely different approach. It's more spiritual than scientific (i.e. they attempt communication at 3:00am every time). I felt like I was watching a scripted and acted event a couple of times, which was a bit of a put off. Like I said, it sparked my interest so I will see if I can catch it again.