When it comes to determining things such as who is the best at something, it can be difficult to not let your personal bias play into the decision.
For this reason, it is a good idea to establish measurable parameters to help you determine how you are making your decision. For instance, if you wanted to figure out who the bet Calgary union is, you would want to pick some measurable parameters. These could be elements such as which union has the best percentage pay raises per year of their contract. For instance, if union A has 10% over 5 years but union B receives 9% over 4 years, union B actually has the better deal.
Typically, you would not make this decision based on just one element but over several such as the amount of paid days off, wage equality, how many grievances there are and how fast they are resolved and many other elements. Determining the best Calgary union is not likely an easy thing to figure out and how you come to a decision is likely based on what you want to measure. It probably will be difficult to find one union that is going to be the best at every item.