No I'd rather have the 5 what if something happens to the one and it gets banned from google or something?
I would choose 5 sites. I would get really scared to have only one site to rely upon. However, it all depends upon the niche and the site. If you have a REALLY great site, that has a ton of potential, then you should spend all of your time working on that site (ie. don't waste your time on other small sites). For most of us however, I would recommend at least maintaining a few different sites to diversify.