Arcane Defense( Complete Arcane, p. 73)
Choose a school of magic, such as illusion. You can resist spells from that school better than normal.
Spell Focus in the chosen school,
You get a +3 bonus on your saving throws against spells from the chosen school.
You can gain this feat multiple times, but its effects do not stack. Each time you take the feat, it applies to a new school of magic.