Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. —Romans 5:18
For in him all the fullness of God was pleased to dwell, and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross. —Colossians 1:19-20
so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. —Philippians 2:10-11
For God has consigned all to disobedience, that he may have mercy on all. —Romans 11:32
English Standard Version (ESV)
Also see "St. Paul's Universalism". This is the fifth chapter of The Inescapable Love of God by eminent Christian Universalist and Philosopher Tom Talbott. In this chapter, he makes a case for Universalism from Paul's writings, especially Romans.
You can find more free chapters from Talbott's book here (scroll to the bottom).
As for 2 Thessalonians 1:9, a universalist would probably translate it:
They will be punished with destruction of the age to come — destruction from the presence of the Lord and from the glory of his might.
The word for "from" here (apo) is ambiguous. It can mean that those punished are punished away from the Lord, or simply that the punishment comes from the Lord; that is, it is administered by Him.
There has been some controversy over the meaning of the terms translated as "eternal punishment" (aionios kolasin). For this I would point you here. In summary, the terms used by the biblical authors to describe eschatological punishment are different from the terms used by those who believed in never-ending torment/imprisonment (the pharisees). There is a discussion of the contemporary usage of aionios and kolasin. Aionios is often used to describe a period of time of finite length (though it could be very long), and kolasin is typically used to describe punishments administered for corrective purposes.
EDIT: I just noticed that the word used in the 2 Thessalonians verse is olethron. Kolasin is used elsewhere, like in the parable of the sheep and the goats.
One last thing. Pithy arguments posted on a Q&A site hardly do an entire theological viewpoint justice, so you should probably look into reading a book.
And if you are looking to buy just one book on biblical universalism, I would highly recommend Gregory MacDonald(a.k.a. Robin Parry)'s The Evangelical Universalist, which gives a universalistic exegesis of the Bible as a whole. And it has a whole chapter on Revelation! Unfortunately, it doesn't have free chapters like Talbott's book (which I consider second best choice), but you can read reviews here (Also see Amazon sneak peek).
(I am not affiliated with any of the books I have referenced/recommended here)