Canon EF 50mm f/1.8 II
This is a lens which we'd encourage any Canon DSLR owner currently shooting with 'kit' zooms to try. The overall image quality when stopped down a bit is very impressive indeed, and the fast maximum aperture offers creative options which are well worth exploring. It's a pity about the build quality and harsh bokeh, but ultimately this lens hits a price:performance ratio that's very difficult to beat.
Inexpensive and sharp, this 50mm prime punches above its weight when it comes to image quality, and functions well as a standard 50mm on full-frame and a portrait-friendly 75mm (equivalent) on APS-C
Build quality isn't great (you get what you pay for) autofocus is slow and unrefined, and bokeh can be somewhat harsh when images are examined critically.