Each magic-user prepares or learns (in the case of spontaneous casters) spells appropriate to his/her play style and the campaign he/she finds him/herself in. The size/composition of the total pool is going to be larger than any one wizard can know.
TL/DR: YMMV
Your mileage may vary.
There are lots of non combat spells, like identify, that still are very useful. There are also lots of combat spells. Things like fireball and scorching ray are obviously useful in battle, but "control" spells like fog spells and grease can be enormously effective for a lot longer than a single turn, even tho they don't inflict any damage.
Spell preparation/spell known selection is one of the more difficult and important things you have to do for a PC. Put some thought into it, imaging what you will do to contribute to combat, obstacles, and social situations.