I use enamels for about 95% of my painting. I don't use one particular brand, instead prefering to pick by color. I've got Testors (small bottle), Testors MM, Humbrol (current production and a few Authentics), and even some Pactra in large and small bottles that are still usuable.
For acrylics (used largely for weathering) I have Testors MM Acrylics and a few small bottles of Pactra Acrylics. Plus I have access to my wife's crafts materials and can use her craft Acrylics - We've found they're great for the various buildings we've built for the little N-scale RR set up we've been piddling with - very large range of colors (sorry no named military colors) but are great for concrete, rocks, bricks etc - She has two brands over there - DecoArt Crafters Acrylic and Delta Ceramcoat Acrylic Paint - get 'em at Hobby Lobby, Michael's and even Wal-Mart. Plus they"re cheap