-Six Flags Discovery Kingdom, California's Great America, Universal Studios Hollywood, and Six Flags Magic Mountain.
Each park had its own take on the scares/fear of Halloween. Here is what I observed:
Six Flags Discovery Kingdom promoted their event as "our scariest Fright Fest ever!" this year as well as "more zombies than ever before!" I do have to hand it to them, there were quite a few scare zones throughout the park walkways and ultimately, it was scarier this year than before. They featured 6 haunted houses, the newest one being named "Total Darkness." My expectations for this house were let low due to the bright safety lights that were towards the floor. I'm assuming having a "total dark" house was a safety hazard and that is why they had these lights on. Slaughterhouse Pig Farms had the best theming out of the houses, but unfortunately there seemed to be a lack of actors/scarers in the maze. The other houses were good, and since this was the first of my 4-park adventure, I felt they really did a good job and stepped you the scare factor from previous years. I did feel though that same of the actors could have made more attempts to scare people; often I would see one and walk passed and they wouldn't do anything. 
Next I made it over to California's Great America for their Halloween Haunt. This was my first year ever going their for Haunt, and actually the first time being at the park since 2003. They featured about 10 haunted houses and LOTS of actors walking around scaring people. The whole park really transformed once it became dark. The houses blew me away with how great the theming was. Each room in each house had tons of props; I think I spent more time looking at the props then looking out for actors! My favorite was the corn maze; they turned the old-fashion car ride track into a walkway, and lined the whole thing with corn/hay bails. People would pop up from behind the corn and you never knew where they were. What really impressed me was that even when I saw an actor or knew where one was, they STILL managed to scare me each time. Kudos to Great America and their attention to detail in their houses, as well as their well-trained actors.
On to Southern California, next stop was Universal Studios Hollywood. Like Great America, I had never been to Halloween Horror Nights before. The whole night began with an awesome "opening ceremony" in the main plaza that was themed to the movie The Purge. As soon as the let us all free, tons of actors came running through the crowds with chainsaws. The first house I made it to was the Insidious house. This is one of my top favorite scary movies, so I had high expectations for this. Before walking in, the outside decor looked just like the house from the movie. Inside was amazing, the rooms were so detailed and almost identical to scenes from the movie(s). The costumes were great and they did a great job at scaring. Other houses included Evil Dead, the Walking Dead, Black Sabbath, El Cucuy, and Monsters Remixed. The one thing I did notice about their scare-tactics was that in each room, they were always behind a curtain and would pop out for a second, scare people, and go back in. The only downside to this is that anytime you walk into a room, you know where they will come from because it is where the curtains are. I was highly impressed for my first experience attending Halloween Horror Nights. (Insidious, pictured below)
Lastly I made it to Six Flags Magic Mountain for their annual Fright Fest. The last time I had been to it there was in 2008. This was the only park that I ended up needing the VIP Flash pass at. The park was PACKED and even right after Fright Fest began, lines looked easily close to an hour. The VIP Flash pass granted us access to all the houses with no wait (at most, I think I waited 2-3 minutes for one). Willoughby's Resurrected was my favorite house, and had great theming and great actors. This house is built underground below the Sky Tower, and has a natural musty smell and look to it. With the VIP pass, we were able to do this one 2 times. Aftermath was their newest house, which was built inside the old Batman Theater. This had really good theming, it really felt like a deserted city, but there weren't many actors in the maze. Total Darkness was at this park too (just like Discovery Kingdom), but it took a very different approach to the fear of the dark. This maze was inside the theater. and once inside, we were put into a group of about 10 people. They gave us a 15 foot rope and we each had to hold onto it. The person in front was given a very small flashlight that shined light about 3 feet ahead and only had a tiny radius. We were then told to walk through the maze, which literally was in "total darkness." We all inched our way along, moving extremely slowly since we couldn't even see where the walls or path were. They had reflective exit signs on a few walls so this helped us continue in the right direction. Actors would scare us any most of the time we couldn't even see them and they were only inches away. The scariest part of this maze is not knowing where you are going an losing your ability to see. We ended doing this one twice, the second time I got to lead the group with the flash light. At times I would reach a corner, and while trying to find my way, I would shine my light right into the face of an actor and they would scare the whole group. Other houses included Toyz of Terror, Weepy Hills INsanetorium, Chupacabra, Cursed, and Black Widow. Willoughby' takes the cake, followed closely by Total Darkness. Oh yeah, and the hypnotist show was hilarious. I wish I could have seen it again and again; lots of laughs and very entertaining!(Willoughby's pictured below)Overall I was very impressed with all of the parks and their unique houses and mazes. The Insidious house at Universal wins as my favorite house, but I might be biased because I love the movie so much. Next year Knott's Berry Farm is on my hit list and hopefully I'll get to revisit all of the parks I made it to this year.
