I found some combos that may sound good to you : (have never used them though)
Call Lightning/Call Lightning Storm + Cloudburst
Boost your damage to d10 by casting cloudburst beforehand.
Call Lightning/Call Lightning Storm + Weather Eye
Predict when you'll be able to get the additional damage without having to cast cloudburst.
Call Lightning/Call Lightning Storm + Summoning of Air Elementals
Same as the cloudburst combo with less duration, and add an elemental.
Summoning Spells + Animal Growth + Augmented Summoning
Storm Rage + Whirlwind or some other wind based spell
When facing other casters, you can cast, but they have to make concentration checks
Greater Magic Fang + Natures Favor
Massive bonuses for your animal companion
Boget Begun + Chain of Eyes
Turn 25 exp into a familiar you can see through.
Wall of thorns + Woodland stride
Not so much a spell combo, but it's a wall you can go through but your enemy can't.
Energy Immunity/Energy Resistance + Fireseeds
Add in a prayer bead and Orange Ioun stone for even more hurt
Shambler + call Lightning
I'm sure this combo is well known by now, but it gets 10d4 con.
Shambler + Thunderhead
Same as above, but better.
Shapechange + Animal Companion
Quill Blast + Baleful Polymorph/Finger of Death
Increase the chance the opponent will fail the save against your Save or Die.
Flaming Sphere + Call Lightning
Basic Druid Blasting. 2 spells 5d6 per round.
Greenbound (lost empires of faerun) summons + obscuring mist in dungeons or vs landbound critters
Mountain Stance + Foundation of Stone
Add caster level + 4 to prevent bullrush or trip and +2 AC (all unnamed bonuses)
Spirit Jaws + Icelance
Use Spirit Jaws to grapple and pin a foe, then conjure an Icelance just for the look on the foe's face and attack it: near auto hit: if it is stunned, move the spirit jaws to a new opponent and continue pounding on the now stunned foe.
Faerie Fire + Obscuring Mist
Give your party concealment, but retain you ability to attack the target.
Snowsight + Obscuring Snow (Frostburn)
Total Concealment vs non-adjacent. Concealment Vs adjacent foes. No hinderance for you.
I hope i have helped you with all this stuff
