Honestly it depends what level your at..
If its super early into the tournament and you are no where near the money, play conservatively.
You should raise nearly any 2 cards when you are 8 or less away from the money. that is the best time to push the medium stacks around.
Right after the bubble bursts, many don't care about busting, they just want to double or bust. So play conservatively after the bubble.
When it is the final two-three tables, you should be raising nearly every hand against medium stacks, and playing conservatively against the short stacks (They don't have much to lose).
Final table, raise nearly any two if your still the big stack.
It's not a be a bully or dont be a bully. It's playing according to the situation, changing gears at the right times..