Camera Simulator

[Polarman]

This site can provide some insight as to why some pictures come out bad.

http://camerasim.com/camera-simulator.html

[Steevo]

The F stop, shutter speed, ISO and default lighting are the ones to pay attention to unless you are hardcore shooting with a lens.

Lower F stop lets in more light and gives good bokeh but can cause lens aberration on the subject, which may or may not be a good thing.

Interesting site, but in the real world its better just to go play with a DSLR, or buy some film and burn through a few rolls.