Paint.net is still one of the very first things I install on a fresh Windows install. It's simple to use but provides enough depth if you want it without feeling overwhelming on opening. Gimps interface has come a long way but it's still not as user friendly as paint.net I feel.
Yep. It's not at the level of Photoshop but it does a pretty good chunk of the intermediate-level features that you might need for more complex projects (e.g. layers)