
My Self |
Not 100% on this, but it seems like sonic, force, and positive/negative are all valid choices.
There's also divine power and the classic fire/cold/acid/electric.

vorpaljesus |
It seems to me that Force and positive/negative energy (oddly enough) aren't energy types by the game's definition. I'm led to believe this because almost every spell or ability lists the five energy types to choose from and they're electricity, fire, acid, cold and sonic.
Can't find RAW for this.
I'd allow your interpretation in my game though.

Blakmane |

Force and pos/neg energy aren't 'energy types', although this is somewhat of an unwritten rule due to the vagueness of pathfinder core. There are many examples of the energy types being fire, cold, acid, electricity and sonic.
I would totally let you take other resistance types though because rule of cool. However, in PFS, I would be ruling the abjuration school power to refer to those five types as per the precedent.