Is it mandatory to apply every minor Core upgrade step by step? I have a site in drupal 6.26 and I need actualize it.

I have two options: 

6.26 to 6.27 to 6.28

or

6.26 to 6.28 directly

What is the best method? Thanks
You can go from 6.26 directly to 6.28.

The most critical part, is the database update, because tables and fields can get modified, added or removed. The upgrade process in Drupal takes care of executing every single database update step.