When I paint an entire room, or sometimes an entire basement, I use an airless sprayer that can siphon paint from five gallon buckets.They are very convenient and can spray a lot
of paint before reloading paint. These are bulky compared to project sprayers and may not be the best option for small projects. But for large areas they work wonders.
I really like Graco Sprayers for DIY. They make such a great product. So the following options are based on how much you will use the sprayer. You are paying for stronger motors and better options.