I enjoy both, but I prefer a good series over a good movie. The much longer form of a series enables more complex stories and greater levels of nuance.

TV series come with more risks and more bad default behaviors than movies. They can always be cancelled in mid-story. Some are forced to tell a story-of-the-week at the expense of the overall story. And there are always producers who want to stretch a series as far as it will go, long after the material has been exhausted.

Despite the potential risks, a series with a coherent long-form story to tell can do things a movie just cannot do. It is possible to tell a story across multiple movies, but doing that amplifies all the risks of a series. If the second movie of your five-part story isn't a hit there will never be another. Movies almost always have to tell a self-contained story, even if they are part of something larger. And if the last planned movie does get made, and is successful, there WILL be more sequels to cash in on the property.

It's worth noting that movies can never replicate a typical novel because the difference in volume of material is far too great. A movie roughly corresponds to a novella. There are plenty of brilliant novellas and plenty of brilliant movies, but at the end of the day I prefer a novel or a series of novels.