9. Jesus acknowledges that he has a God.

Jesus said, “Do not hold on to me, for I have not yet ascended to the Father. Go instead to my brothers and tell them, ‘I am ascending to my Father and your Father, to my God and your God.’” [John 20:17]

Trinitarians attempt to explain such statements away by saying that it was only the human side of Jesus being subservient to God, not his divine side. The problem is that later in the Bible, after Jesus has ascended and cast aside all human limitations, he is still saying “my God”:
I am coming soon. Hold on to what you have, so that no one will take your crown. The one who is victorious I will make a pillar in the temple of my God. Never again will they leave it. I will write on them the name of my God and the name of the city of my God, the new Jerusalem, which is coming down out of heaven from my God; and I will also write on them my new name. [Revelation 3:11-12]

So their explanation of the human side of Jesus doing the talking falls apart when he is still using the same language of subservience as he did whilst he was here on earth. Moreover Jesus surrenders his kingdom to God:
Then the end will come, when he hands over the kingdom to God the Father after he has destroyed all dominion, authority and power. For he must reign until he has put all his enemies under his feet. The last enemy to be destroyed is death. For he “has put everything under his feet.” Now when it says that “everything” has been put under him, it is clear that this does not include God himself, who put everything under Christ. When he has done this, then the Son himself will be made subject to him who put everything under him, so that God may be all in all. [1 Corinthians 15:24-28]

If Jesus is fully God, and an equal member of the Trinity, then why does Jesus give back his kingdom to God the Father when our world comes to an end? In addition, why is Jesus made subject to God after he has surrendered his kingdom over? Clearly, God is forever supreme over all, including Jesus.
10. God is above Jesus in hierarchy.

But I want you to realize that the head of every man is Christ, and the head of the woman is man,and the head of Christ is God. [1 Corinthians 11:3]

This statement was uttered after Jesus had ascended and cast aside his human limitations. If the Trinity is true, then surely Paul (the author of the above statement) would have uttered something along the lines of “man is the head of a woman, and God and Christ are the head of man” which would imply a horizontal relationship between the persons in the Trinity. Clearly, God is above Jesus in this hierarchy, implying no co-equality between them, and thus there is no Trinity.
References
1 – Homilies on John, tractate CV, chapter 17.