Spoiler:
Fighters are the purest form of military might outside of the Warrior npc class. The class was made to fill out all possibilities of a military outfit. You want a phalanx? Fighter. You want archers on the wall? Fighter. You want shieldmates? Fighter. You want pikemen and dragoons? Fighter.
Just play an Dwarf Fighter (Unbreakable) if you want to resist spells better. Getting endurance, diehard, and steel soul at first level pretty much sets you up for being a very durable fighter. If that is not enough just take two traits for your will save and fort save.
With an array like:
STR 16, DEX 14, CON 14, INT 12, WIS 14, CHA 7
and saves like:
FORT +5, REF +2, WILL +3 (+4 Vs Spells and Spell-Like Abilities)
Plus with 12 INT you still have 5 skill points without having to cannibalize your wisdom score.
At 2nd level and every four their after an unbreakable fighter gets a +1 bonus to will saves up to a maximum of +5 at Level 18. At Level 20 they become immune to mind-affecting effects.