Both my birth experiences were pretty positive (imo!), the second one a much more positive experience than the first probably because I knew what to expect this time. With DD1 we got to hospital at about 0720, my contractions having started coming quite strongly and regularly very suddenly at about 0600 (I'd had an examination the day before and the doctor told me I was 2 cms dilated - without even knowing it!) I didn't want to get on the bed straight away so I paced the room although I was on a monitor so couldn't go very far. I think the walking/pacing helped me a lot, as I also did it 2nd time round! I used gas and air, then pethidine, but the mixture of the two made me feel totally out of it. I was told to lie down on the bed after my waters broke, and was told to stay lying down, which I didn't really want to do, but was too out of it to argue. I didn't really have the feeling of "needing to push" but dd1's heartrate was dropping so she was delivered with the help of a ventouse. Worst part was not being able to sit down properly because of stitches!
DD2's birth, however, was a much more positive experience. I said from the start I didn't want gas and air but would probably have pethidine. We got to hospital at around 3am (very antisocial!), and as when I was in labour with dd1, I paced around as much as I could, leaning over the bed and swaying my hips from side to side and backwards and forwards through the contractions (this really seemed to help me - don't know why, and it just seemed to come naturally too). After a trip to the loo, where I had a really strong contraction, I told mw's about the contraction and they suggested I got up onto the bed and leaned over the back to see how that felt. After I got on the bed, they asked me if I liked this position - to which I said no(!) - but I felt a really strong urge to push. My waters broke as her head crowned, which I think helped get her out.
Goodness, that's very longwinded! I hope I've said something which will be of help to you - basically I found walking around during labour and "swaying/rocking" through the contractions extremely helpful, and being in an upright position as opposed to lying down was definately the best way for me! Before dd1's birth, I tried to watch as many "true life" birth programmes as possible to prepare myself for the "goriness" of it all. I think it helped as I imagined the "worst possible scenario" and, luckily for me that didn't happen. Both births were a positive experience, and it's really true what they say - it is painful but you soon forget the pain when you've got your wee one in your arms! (By the way, dd2 will be a year old tomorrow, so this is bringing back lots of memories for me!)