My best birth (I actually enjoyed it!) was the one where I was most 'alone'. The midwife didn't arrive in time, I laboured alone in the bath apart from the very last 5-10 mins, when my DH was really annoyingly on the phone to the paramedics and relaying their really unhelpful instructions. I'd have much preferred him to stay out of the room for the whole thing (I laboured and gave birth in the bath).
That may not sound ideal, but I felt very calm and in control of (almost) the whole process. Very weirdly, I'd had quite a strong premonition all throughout the pregnancy that I might end up birthing alone, and had read a lot of birth stories about unattended/unassisted birth, what to do if the baby doesn't breathe after birth, what positions to try in the event of shoulder dystocia, etc, so I felt very well prepared.
HOWEVER, that was my fifth birth, and my fourth at home, and I have a particular type of labour (pretty rapid), which by that point I was fairly expert upon - and I am the sort of person who always does a lot of reading and research, and is very self-sufficient during labour, not needing or wanting much support from others.
Sorry for the essay: I suppose my main point is that it depends very much on YOU; your mental attitude, your level of 'experience', the kinds of labours you may have already had, etc. HTH.