All of the above.
I make the most money with my large site, but my smaller sites (1 page to 5 pages) are contributing a constantly increasing % of my income.
I spend most of my time on my big site, but also spend some time on the smaller ones. Usually I put them up and optimize them and when they start taking off I start expanding them and sprucing them up.
That can be a two edged sword – sometimes the engines don’t like the improved site as well as they did the simple one. I find though that this corrects itself sooner or later as long as I continue to be a stickler about SEO.