This is a subjective answer, but the question itself is probably fairly subjective-ish to some degree of meassurability (I jest to make a point).
This answer is slightly less off-topic than Koviko's comment and I will try to expand upon what he said in it and merge it with your question to provide you some additional guidance.
Your choice of "role" is exactly that. How you play, whether mostly solo, mostly with a group of friends, or mostly in public games will make a huge difference in what will work best for you.
In addition to that, how well you are geared compared to the content you are in will also make a difference in the number of options that are viable to you.
Those subjective qualifications stated... let me give some guidance.
Rule of Thumb:
1) Thou shalt not play in content where you are killed by one hit.
It will most likely not be fun. If you find that your are unable to survive even one hit, you will not be able to enjoy the game because you will spend more time waiting to revive than you will have alive. I am not trying to break rule #2 by saying "Thou Shalt Not...", but to most people I know, the game is more enjoyable when you are staying alive the majority of the time.
The easiest fix (early on) to improve upon your survivability once hitting level 60 is to start looking for gear with All Resist on it. Armor is not really optional to get, it will come on all your gear. Resists are optional and have the same effect as armor when they are equal (and much greater effect when they are lower). Do not forsake all damage for survivability, but strive to achieve a balance that brings you the greatest enjoyment between survival and large pretty white & yellow numbers.
Rule of Thumb:
2) Thou shall neither tell another player how to play nor let them tell you how to play.
By this I mean that you should figure out what it is that you enjoy doing most (what skill is your favorite? Use it, find things that synergize with it). Do not assume that the barbarian will leap on top of you and stun the monsters off of you 2 times. Similarly, do not expect a monk to run over and heal you.
The game will be best enjoyed if you do what you want and let others do what they want. That said, if you play with certain people regularly, it is easy to develop strategies that as a team will make you stronger. (example: rotating Crowd Control type skills in a particular order so that you are not using them at the same time)
Rule of Thumb:
3) Generally speaking, with other players in the game you should focus more on damage, but if you play by yourself you will have to focus more on survivability.
That is not saying you may not build for damage when you solo. In point of fact, the skill Archon make wizards very capable of dealing damage quick enough to kill many rare and elite monster packs (before the wizard gets killed).
However, if you play by yourself, you will also need to take into account the effects and bonuses your hirelings will provide.
Do what you enjoy most!