I would definately have to say the people. I don't think I have ever had a truely bad day in 6 years of doing this. I may have bad moments, but never a whole bad day. There is always someone or something to laugh at or with, how ever you may look at it, you make some great friends (atomic frog and wife are my favorites!), and the care people show when something bad does happen to a person or family member.
The pay is a great benefit, locations.... Florida, my kids loved getting to come down and take a mini vacation to the keys, and while outage hours are long and tiring, the other time doing other things is great. (Was nursing during non-outage times, now a permanant nuke worker).