There are so many.

One of my favorites I prayed in some of the worst times!!!!!

Psalm 116

I love the Lord for he heard my voice;
He heard my cry for mercy.
He turned his ear to me.
I will call on him as long as I live.
The cords of death entangled me;
the anguish of the grave came upon me;
I was overcome by trouble and sorrow.
Then I called on the Lord:
"O Lord save me!"
The Lord is gracious and righteous;
Our Lord is full of compassion.
The Lord protects the simple hearted;
when I was in great need he saved me!

This verse really helped me when I thought I was at the end of my rope. It's a very powerful verse. The power of prayer is so true!