Enter the Great Swordsman! Pirate Hunter Roronoa Zoro!

In the manga the crowd that is scared by Zoro's name is in the bar, but in the anime it's people on the street.
 
Luffy seems to know he's looking at Zoro despite never seeing him before. Zoro was originally designed to be a member of Buggy's pirate crew, but was changed at some point to a pirate hunter.
 
In the manga Zoro saved Rika in the street and cut Helmeppo's dog. Not her mother's bar. The scene where Luffy strikes Helmeppo also happens in te street, rather then the tavern.
 
Nami appears in the tavern this episode. Her appearance is marked with a chime, but in the canon story she doesn't appear until after after Zoro joins Luffy. She later is seen raiding the Marine base for the maps.
 
Morgan says Helmeppo isn't worth hitting, after he just punched him.
 
Coby seems to know that Luffy is being chased around the marine Base, despite having arrived well after Luffy. The scene of Zoro's thoughts on Kuina is much shorter then how it was depicted in the manga.