Don't get me wrong, it is not really a bad lens, but, it is not a great lens.
many photographers bubble about this lens because they are comparing its image quality with the 18-55mm kit lens and it does win that contest hands down!
The 18-55mm kit lens is an el-cheapo that was developed by Canon, not to be an excellent lens, but to be a part of the first sub-thousand dollar DSLR combination - the original Digital Rebel.
The "Nifty-Fifty" was developed for just the same reason, not to be a great lens, but to enable Canon to package their Rebel EOS Film Cameras at a competitive price.
What Canon did was to take a very good lens, the 50mm f/1.8 Mark-I and water down its construction and features to make the "Plastic Fantastic" cheap to produce.
They began will all plastic construction even the lens mount and they removed the focusing scale which IMO is very important - especially when shooting in lower light levels.
The result of the poor construction was a fragile lens that is more likely to fall apart than most "normal" lenses. I have been a photographer for fifty years, most of it professionally; including several years as a combat cameraman in Vietnam. I have NEVER totalled a lens until I was given the "nifty-fifty". All it took was a slight knock against a door frame and the front element was rolling on the ground. There is not much use in photography for a two piece lens.
Sure, buy the lens because it is cheap. However, don't expect a great lens for that price. IMO, your money would be better spent if you took what you would pay for a new "Nifty-Fifty" and added some additional funds to purchase the much better built Mark-I on the used market.
By the way, the Mark-II replaced the Mark-I and a used Mark-I costs more than a new Mark-II. That might give you an indication as to the relative merit in which these two lenses are held by photographers.
Or, if you can afford it, as stevieboy278 recomends, "get the 50mm 1.4 instead - its sharper, focusses better, and is built like a tank . .. . " Additionally, the bokeh is so much better than the five blade aperture of the Mark-II.