I own a NEX5, and it is the best camera Sony has put out in a VERY long time. And it has really helped Sony revive the reputation of their cameras.
When choosing photo quality, the size of the sensor and the lens are the 2 biggest components. Everything else helps, but can never make up for these two components. And the screen shows you what you are shooting, and what you just shot, so the specs of the screen are extremely important. The NEX5 screen is huge, hi-res, and tilts. This means you don't have to be looking straight at the screen to view it properly. Overhead shots are a breeze, and no more bending your knees with tripods. The video is amazing too, and has its own button.
With its small form factor, proper lens, huge sensor, tilting LED screen, and HD video, this camera was an instant hit. It can also take great shots with little light.
The only nag is its controls. They are oversimplified, and the advanced features are buried in menus. If the shortcuts aren't what you use, there is no changing them, but they do cover most use cases.
The best part though, is my aunt was able to pick it up and use it right away. So without a DSLR camera, almost anyone can enjoy DSLR photos, without the weight, the geeky look, and any prior knowledge of photography.
It's been a while since the NEX5 was released, and there are a lot of MILCs now. The screens have all gotten better, and HD video is pretty much a given. At this point I am sure there are other comparable offerings from other brands, but there is no doubt in my mind that the NEX5 was a trailblazer in the MILC market.