In some ways the question in the title is largely spurious. It does not really matter who is the best - it only really matters who you can get a job with. Very few people have a genuine choice between easyJet, Ryanair, Germany Wings, Jet2 or Monarch. The best someone often has is a choice between leaving one and joining the other. In most cases people are just desperate for jobs and are only in the running for one company or the other, and whatever job they get offered they grab gratefully with both hands.
Regarding the long-term picture, I think I agree with our easyJet 'Alumnae' in the form of Craggenmore and Bokkenrijder. They have both flown for what is arguably the most reasonable of the low cost carriers, and the one for whom I still work - easyJet. I think that the cumulative effect is fundamentally negative, even though I always enjoy my job. There is so much that is good about working for easyJet, but if I was flying the line (particularly at a big base like Gatwick), the hassle factor is enormous over a long period of time. Every now and again is fine but five earlies is killing for most people over any length of time. As has been suggested, to do a whole career without going part-time would be difficult. EasyJet works for me, but I live half-way between the sim and the airport and get home every night. I am not counting the days until I retire but if I see a couple of standbys on my roster I am far from disappointed! Due to ageing relatives and kids married here in the UK, the sandpit is not a practical option for me at the moment. I am therefore of the view that I am a lucky man to be working for easyJet and cannot fault it. I do, however, think that a career in aviation is hard work for anyone - regardless of who you work for. The low cost carriers are even tougher places to be, but are the only option for many people. In terms of job security, remuneration, safety standards, training quality and so on easyJet would be very hard to beat. To fly full-time for 20 years, however, would be a big ask. I have unwittingly followed Bokkenrijder's advice and been financially cautious in order that I am not beholden to anyone in my later years - that would strike me as wise. You will always have your numpties who live beyond their means, but most people are sufficiently sensible to prepare for the future. Whether it is a million times better in Emirates or whatever I really do not know. I suspect there are frustrations working there too - there is no Air Utopia out there that I can see.