dig. camera suggestions

I am looking to buy a digital camera. Any suggestions for a high
resolution camera in the $300-$500 range? My main concern is that the
camera can take high resolution photos and can handle all different
lighting situations.My current Canon digital camera (4 megapixels) is
horrible for night photos. I love the details in the photos I take with
my 35mm manual, but like the conveniance of a digital camera. Any
suggestions for a camera a little beyond basic for an aspiring
photographer? I would be willing to pay more for a camera if it was
really going to make a difference in detail, that is my main concern.
Thanks for your help!