Taken is the best example of what an action movie should be. It's short and sweet and packed with action from the get go. You care for the main character and you route for him to succeed. You know he is going to win in the end but the ride is enjoyable as hell. Another good example of this according to me, is Unstoppable.
All of that said, I don't really think Taken needs a sequel, I saw everything I needed to see and I was satisfied. I don't blame Fox though, it was a big hit and made some bank, so of course you have to explore it. Below is a nice example of viral marketing from the sequel. Happy Father's Day from Liam Neeson.