With the relative nerfing of lightning bolt, IMO, in 3.5 I have to say Fireball has been a better choice for my mages. Energy substitution is a big help to any mage and makes up for the fire immunity issue.
Of course then you don't get to hear the "lightingboltlightnigboltlightingbolt" jokes.
Of course then you don't get to hear the "lightingboltlightnigboltlightingbolt" jokes.