I have a little experience with this one... I am a bit of an old house nut, and lately a nomad, as I have owned three homes in 5 years. I also spent many years building trade show booths around the country for a home decor wholesaler, which means a LOT of painting. Aside from that my father and uncle are professional painters, and a close friend and his father own a small commercial painting company (hospitals, condos, malls).
So I'll share my thoughts. I love Behr interior paints. My preference is flat enamel for walls, semi gloss for trim or furniture. Why do i like them? They work as well as anything else I have tried when new. But the best part? If you go back there five years later for touch up paint and all you have is a code, the color is going to match, no matter which home depot you go to. They are very consistent in their matching, and once applied the paint does not fade. They are also really good at scanning and matching a color (such as Benjamin Moore's historic colors). If I need primer, I like Kilz latex for interior work, although their latex doesn't really block anything well. You need oil primer to block stains, but the fumes suck.
Outside, I find that oil based primer is a must. Latex primer just does not stick for long, no matter how great your prep is. I am partial to Hallman Lindsey, which happens to be made about a block from where I work.
Attached is the most recent painting projects... new baby's room, and porches on the house. In the baby's room the skinny white cabinet was a homemade item.