As a followup to this question, what non-human, non-droid characters in the prequel trilogy spoke Basic? It seems like significantly more, but I have not watched these prequels more than twice...
Fodesinbeed Annodue, the Troig pod racer announcer (though only his left head)
Ki-Adi Mundi (Jedi)
Jetster Dexter (diner owner)
Lama Sul (the cloning scientist)
General Grievous (droid or no? - used to be an alien at least)
The Chagrian who is the Chancellors Aide.
Zam, the bounty hunter who attacks Padme
There are a few non-human younglings in the Jedi temple who greet obi-wan
The man selling death sticks in the bar
Nute Gunray, Minister of trade for the Trade Federation
Wat Tambor, the Foreman of the Techno Union
Episode 3 The Pau'ans (of the planet Utapau)