Oooo I can help here I am working on an evoker for an all wizard campaign (silly I know).

Anyway the absolute best things I've been finding involve Elemental Savant, yeah 2 levels lost but getting your native plane changed is a great boon with planar bubble.

What I was doing was Evoker 5/ Elemental Savant 10/ Archmage 5 (though due to changing some things I think aside from getting mastery of shaping archmage becomes more of a burden due to feat requirements.)

What really makes this work are certain spells and feats though. I was focusing on fire, purely because searing spell metamagic from sandstorm gets through all resistance and still does half damage to those with fire immunity.

Now an interesting thing with going for fire, becoming a fire elemental, and using Planar bubble. Basically you get an area around you that you can damage people with, as well as gain the benefits of being on the plane of fire, aka all fire spells maximized and enlarged! Enlarge not that great but free maximize is awesome. Other fun plane things could be being an air elemental, and getting objective gravity... so you can travel by falling places...which seems utterly ridiculous.

Now take arcane thesis on your favorite blasty spell, I personaly was going for Otilukes freezing sphere to be a silly master of the frozen flame, allowing me to add a ton of metamagic on for free like searing spell, and eventually allow it to be twined in a ninth level spot while still having as many +1 slot metamagics on it as you can. Either way it seems like a great way to deal a ton of damage fast, and the freezing sphere stops people from running away from you, a fire elemental, in the water. I was really thinking I was going to change the archmage to something else because I would rather take some extra metamagic, or even arcane thesis more than one spell just to be able to use those spells in extremely silly ways. The elemental savant just greatly boosts you DC and caster level to penetrate SR with all spells of your element, and getting searing spell just means you get to ignore anyones resistance to your element, and still damage people who should be immune (note: be careful this means you could hurt yourself!)

Also thinking of being a focused evoker to get as many spells as a sorcerer per day, I mean if you focus on blasting to the extreme who needs a wide variety of schools?