1 Hold Portal: I have seen this be useful many times. Enemy thinks they're smart w/ an adamantine door or whatever. Mage invisibly goes over and casts this on said super door, then the party creates their own entrance or teleports (wall of force/stone'ing the hole closed, if applicable). Never stops being funny.
2. Arcane Turmoil: Or as I call it, "Arcane *****slap." Just plain better than normal dispel when targeting anyway.
3. Anticipate Teleportation: This and the greater version singelhandedly invalidate scry-buff-teleport!
Explosive Runes: Great for pranks, or building up a massive quantity of during downtime.
4. Dimensional Anchor: I hate it when mages/outsiders teleport away.
Mass Resist Energy (3rd for cleric/druid): Instantly neuters many dragons and others.
5. Reciprocal Gyre: I both love and fear it. Man, does it make you pay for buffing!
6. Greater Dispel: It's just essential.
Guards and Wards: I've always wanted to use this, but have never had the chance.
7. Spell Turning: Another one to screw a caster with.
8. Prismatic Wall: The ultimate wall spell. Complete protection, horrific effects to anyone that crosses, and you can Flyby Attack in and out of it safely.
Dimensional Lock: Essential for a high level battlefield controller, if only there were a lower level version w/ less duration.
9. Effulgent Epuration: Why, I would in fact like immunity to (harmful) targeted spells, thank you, very much!