We do not know for certain whether any of the Gospels were written in Aramaic. An early Christian writer named Papias wrote (c. A.D. 120) that Matthew wrote the oracles of Christ "in the Hebrew tongue." This is ambiguous because "the Hebrew tongue" could refer to the language known as Hebrew or to Aramaic, which was the tongue commonly spoken by Jews at that time.
Throughout Church history the accepted opinion has been that Matthew wrote his Gospel in Hebrew, but since the last century the view has become common that he wrote in Greek instead. Recently there has been a number of scholars returning to the earlier opinion that he wrote in Hebrew or Aramaic. Some have suggested that Mark and Luke were also written in Hebrew or Aramaic.
Two books by scholars advocating a non-Greek origin for some of the Gospels are The Birth of the Synoptics by Jean Carmignac and The Hebrew Christ by Claude Tresmontant.
In Jesus' day Hebrew was not spoken by only the priests in the Temple. It was also used in the synagogue liturgy, and it was the language in which Scripture was read. Many Jews had at least some understanding of Hebrew, even though it was not their primary language.
This fact has apologetic implications for Catholics. The next time someone attacks the Church for having used the "dead language" of Latin in Church services and older editions of Scripture, point out that Jesus worshipped in synagogues where the "dead language" of Hebrew was used.
We do not know whether Pilate used a translator in his conversations with Christ. As a Roman governor, Pilate would have known Latin (his native language) and Greek (the international language). He might also have known some Aramaic, since he was governor of an Aramaic-speaking territory. Even if he did not know Aramaic, many Jews would have no problem conversing with him; Greek was the language of commerce, and many Jews knew it from their business dealings. Thus Jesus' conversations with Pilate might have been conducted in Greek.