Alchemist

Alchemy is an effective (yet somewhat expensive) method to gain spellcasting without spending PP. Alchemists craft their extracts (similar to potions, but 1/5 the cost) each morning, and can only carry a limited amount each day. This class pairs well with most, but is especially useful as a means to indirectly access Spellcasting for Dwarf Mages, the Monk class, and fighters who have taken the Master of Weapons feat.
Alchemists combine with anything, add extra spell versitility (you can "cast" multiple spells per round before taking the Rapid Cast feat), but are VERY expensive to operate. A single days worth of spells can easily cost 3 Frags (roughly $600).
Primary Stat- INT
Focused Skills- Alchemy and Enchanting, Guild Magic, Summon Magic and Alteration Magic or Life Sciences, Physical Sciences and Social Sciences. Whips and Thrown Weapons skill is needed if you wish to fully take advantage of the Bombchymist feat.
Feats
Spirit Shunned (if playing a non-Spellcaster)
Self-Experimentation
Poisoner (for weapon users) or Bombchymist (requires Whips and Thrown Weapons skill to be effective)
Learn Spells (take multiple times)
Speedy Mix
Combine Potions
Master Alchemist

Taking Spirit Shunned and Self-Experimentation at a higher CL is a decent way to grant a character a reasonable amount of useful spells at relatively low feat cost.