My favorite sura is Ad-Duha, because the first time I read it, I was having a really hard time with things, and its message cheered me up so much I cried.
"By the Glorious Morning Light
And by the Night when it is still,-
Thy Guardian-Lord hath not forsaken thee, nor is He displeased.
And verily the Hereafter will be better for thee than the present.
And soon will thy Guardian-Lord give thee (that wherewith) thou shalt be well-pleased.
Did He not find thee an orphan and give thee shelter (and care)?
And He found thee wandering, and He gave thee guidance.
And He found thee in need, and made thee independent.
Therefore, treat not the orphan with harshness,
Nor repulse the petitioner (unheard);
But the bounty of the Lord - rehearse and proclaim!"
And have any of you ever had a moment when you're really stressed, and you opened the the quran to calm yourself down, and the first thing you read concerned what was troubling you?
That happened to me one time, when I was really upset at something my brother was saying, when we got into an argument on something islamic, and i said one thing and he said another, then i got the proof for my argument, and he still was arguing with me really harshly. So I went to my room and I opened the Quran to a random page, and I forgot what surah it was, but it basically said to fight for whats right, even with your own kin.
And it made me laugh :]