This one is pretty self-explanatory. There's alot of S.D.A, especially because its 4Kids dubbing it. Sometimes they add lines, or change them, which make them sound so stupid.
In the first episode: "You stepped on my toe!"
Or "I wasn't going to hit you!" uh, yes you were.
Then, there were a few ones in the Buggy arc, too. Luffy had two that I thought were so annoying:
"Yowza!". Or, "Zolo, it's time to golo!".
And let's not forget about the awful vegetable puns in the Kuro arc.