I have had all of mine unmedicated except the last one. I was given an IV drug (can't remember which one) and I will never do that again. On top of not doing much for the pain, I was hallucinating and had to really focus on the fact that I was having a baby. It was nuts. And I lost 2 hours with my baby. I can't remember his first 2 hours of life. Gone.
Deep breathing helps me through it the best. But that is what works for me. I have to have my DH there to remind me to breath because I have a bad habit of holding my breath. And I have realized when I get to the point of "I can't take this anymore" it is right at the transition to pushing. SO now I know when I feel that, it is almost over.
I will say that I have nice quick labors, I am not sure I could do it for many many hours, so just remember that if you need to, there are other options.