Lifelong Edmontonian here.
Overall Calgary and Edmonton are pretty similar and each offer a lot a great quality of life, so really I don't think you can go wrong with either one.
Calgary definitely has more of a "big city" feel to it, whereas Edmonton is more quiet, though the populations are more or less equal.
Edmonton's transit leaves much to be desired, though if you live along the LRT line it hits most areas of interest. It is undergoing significant expansion over the next few years.
I think Edmonton has a much better university-town atmosphere than Calgary, especially in the Garneau/Whyte Avenue area that surrounds the University of Alberta. Downtown isn't the most active of places, but things have improved dramatically in the past 5 years and with a new arena/museum/towers planned it can only get better. For outdoor activities, the river valley is a huge attraction -- the trail system is massive and is one of my favorite places in Canada.
Edmonton has a bad reputation for crime, but its pretty overexaggerated. I haven't had any problems.