I had an epidural with #1 and nothing for #2.
But #1 was The Birth From Hell and I could barely see straight I was so tired and exhausted and in so much pain by the time I had the epidural, whereas #2 was straightforward. Long for a #2, but straightforward.
I'd decided in advance that, assuming everything went smoothly, I didn't want pain relief for #2. Lots of personal reasons: mainly trying to recover faith in my own body after a serious illness inbetween children. So I didn't have the temptation of drugs (I'm bloody minded like that ;) ).
Really wasn't all it's cracked up to be though. There was no Mother Earth moment and I didn't feel like superwoman, there was just a hell of a lot of pain. Recovering so quickly though was awesome: felt normal again within minutes.
I think if you want a natural birth then you need to be very decided about this, since there will be moments when you could 'crack'. You also need to tell your care team so that they don't offer you the drugs. However you also need to be realistic. If you have been in labour for 30hrs with no sleep, nothing but water etc etc (like I had been), then you would almost be a fool not to take some drugs: I firmly believe that if I hadn't had that epidural I'd have ended up with a section since I'd simply have been too exhausted (the epidural gave me an hour or two to recover my strength before it was time to push).
And either way it really doesn't matter. The focus of childbirth should be on getting a healthy baby and a healthy mummy at the end of it all. The process is irrelevant and no way of giving birth is 'better' or makes you more of a success or a better mother than any other way.
Here endeth the lecture.