There's no single "best" film
Every application and company is different. Sure, there are commonalities, but there's a lot of detail that film experts and local reps consider when suggesting the optimal stretch film for an application. The "best stretch film" is relative - based on your goals, circumstances and expectations.
Film gauge, pre-stretch capability, puncture resistance, tear propagation and other performance characteristics are examples of the specs which the film experts will consider with you as they help to select a film.
There's a basic difference in how films are manufactured though that's interesting to understand as someone who relies on the "system" of stretch wrapping equipment and film to safely deliver your loads to their destination.
Films are either blown or cast.
Let's look at the difference in the manufacturing process. Please note - this is intended to be informative and not to specify one method or material or another.