I would say there are a few options that would work well. I'll put it out there right now though, DO NO go with the Nikon J1 you mentioned. Image quality really isn't much of a step up at all from most point and shoots.
First, is the Sony NEX C3. It has a sensor that is the same size as DSLRs but the body is half the size. You can find this one used for around $350 (rarely under 300). Great clarity and low light for the price, but mainly it is a DSLR sized sensor with fast accurate auto focusing.
Next is the Canon T3i. The T3i is probably the best image quality you can get under $1000 at the moment. The main problem with the T3i is that it has no form of continuous auto focusing for live view/video. It is an incredible budget production camera, but you will have to adjust nearly everything manually to achieve good images. You can find T3i cameras for as low as $450, but they generally retail for $600.
Lastly, I would take a serious look into the NEX 5r from Sony. Honestly this is THE camera I would recommend to you as a flogger. It is BY FAR the fastest autofocusing, framerate etc. Low light is incredible and it has a topside flip up screen. Here is what makes it so awesome for vloggers though, it is WIFI enabled with an app store. You can literally upload directly from the camera to YouTube. So if you are ever just at a random cafe and want to upload some random thoughts to YT, you can do so without having to use your phone camera. This retails at $600, but again I have seen them closer to $450. It is totally worth waiting a paycheck or two. In my opinion.
Hope that helps!