At first glance, it may seem like SW:TOR stats are very complicated due to the fact that there are many new stats in Star Wars: The Old Republic not previously seen before in MMORPGs.
However, the truth is that SW:TOR stats have been simplified to the point where the “best stat” for all classes is always one particular stat. The way this works is that different stats do different things for each class.
For example, the Jedi Knight’s main stat is Strength. Normally, Strength increases your effectiveness in melee combat, but for the Jedi Knight, it also increases the damage of the Jedi Knight’s force abilities. This way Jedi Knights do not have to worry about the willpower stat (which also increases the strength of force abilities).
However, for everyone else (including the Jedi Consular), strength only effects your melee damage and your melee crit rate.
Each class has a primary stat that affects their core abilities. For example, the Jedi Consular's primary stat is Willpower. Each class has a different primary stat, but Republic/Imperial classes share the same stats (Smuggler/Imperial Agent both have cunning as their primary stat for example).