Pretty much everything has been covered, but I'll add my 2 cents. Either city can be the "best" depending on the person who wants to live there.
1.) Both have major crimes, including gun crime. In Vancouver it's mostly Asian gangs/Nightclub shootings, and mostly black gangs in Toronto (usually around housing projects in poor neighborhoods). Either way, neither is necessarily safer. Most people consider both cities to be "safe" regardless...Take your pick...
2.) Vancouver by far is considered a more attractive, "green" and beautiful city. It is surrounded by the Rockies, the ocean, and has very clean air and greenspace. Toronto has some nicer park areas, but pollution is a much bigger issue here overall. Many people use the term "dirty" or "industrial" to describe Toronto. You will never find the same kind of "parklike" atmosphere that you do in Vancouver in Toronto, IMHO. Vancouver is always rated as one of the top cities in the world and for quality of life. Toronto does have some nice areas, like the Beaches.
3.) Both are expensive as hell, with Vancouver coming out on top here (more expensive). But both cities offer suburbs and surrounding smaller cities to live in for less.
4.) Job opportunites depends on your field. Vancouver/Victoria is known for its IT community, you may want to move to Toronto if medical research or business is your field (although UBC also excels in research). I would say that BOTH are hotspots for most fields.
5.) Vancouver has a very large Asian population. It is the largest in North America, I believe. I would say Vancouver is multi-cultural overall, and accepting of gay people and alternative lifestyles, but Toronto is known for its vibrant gay scene/neighborhood and huge mix of immigrants and cultures. If culture (other than Asian) is your thing, Toronto wins. Vancouver culture is often more the "granola" type. People in Vancouver are generally more concerned about the environment, their health, outdoor fitness, and nature.
6.) Both cities can be friendly or mean, it depends on who you talk to. Like any other large city. I have found Vancouver people to be more sophisticated, but yet relaxed and friendly at the same time. Again, it's who you talk to.
7.) Both cities have their weather pros and cons. Vancouver can have gorgeous weather, but it does rain a lot during certain seasons. I don't mind the rain, so no big deal for me. Toronto has nice fairly hot summers, but they also get snow and cold temps. in the winter, including some major storms (not usually nearly as bad as the Prairies, though). Vancouver weather in general is pretty mild in the winter. I would say that either could win here, depending on what you prefer.
Personally, I like both cities. I always have a bias towards Vancouver though, just because I love the mountains and "urban chic hippie" lifestyle. Toronto I love for its size (big city girl) and pace. Good research going on there too. It's a very connected city with lots of media and things going on.
Either city is great, but if I had to choose, I'd pick Vancouver...but have a home in Toronto too...
Good luck and best wishes wherever you go!