"Sharknado Week" has been an exciting time for me. I love all of these new shark movies coming out, and I love the "Sharknado" movies being the focal point to all of them. The Asylum's "shark-o-verse" (or whatever you'd call it) really brings out the kid in me. I'm not sure how they managed to make so many different shark movies, but they keep pumping them out of their factory at an alarming rate. And, I know that "Sharknado" has a huge cult following, and I do love all the movies in that series, but I still feel like the "Sharktopus" movies are somehow better.
It's difficult to compare them, aside from the shark stuff they don't have too much in common. sharknados are forces of nature, while Sharktopus is a genetically altered shark-octopus hybrid. As of right now, Sharktopus and its mythos is a lot more nuanced and complex, even if it is silly. With "Sharknado 5" premiering shortly, and the trailers hinting at more mythological and even ontological roots to the history of sharknados, I guess we'll be learning a lot more of the global history surrounding the natural disaster and how it seemingly has become an epidemic.
As of right now, I really still prefer the Sharktopus franchise, and I wish it'd get more love. "Sharknado" gets all sorts of merchandise, and a bigger budget to play around with. At least according to "How to Survive a Sharknado" (a tie-in book to the second "Sharknado" movie) we know that both the sharknado natural disasters and Sharktopus exist in the same universe. So that's something.
So yeah that's my little opinion on both series. But funny enough, I feel like the "Mega Shark" series is better than both of them. I might be in the minority there, but that's how I feel.