[sblock=IceFractal]Just looking in the SRD here, and excluding even defensive spells that any Wizard might prepare just in case, or non-violent combat stuff to deal with bar fights/angry mobs:
8th Level:
Greater Planar Binding - Extraplanar creatures can serve as a source of information or useful powers, not just combat aids.
Discern Location - Find where anything is, no matter what.
Prying Eyes - Allows you not only to scout faster, but also research faster and/or observe an experiment from multiple directions.
Telekinetic Sphere - Easily move large objects, contain dangerous materials, etc.
Polymorph any Object - Too many uses to even count.
7th Level:
Mordenkainen's Magnificent Mansion - Live large, even in the most crowded city or the most desolate wasteland, for one spell slot a day.
Greater Teleport - Travel safely in seconds.
Greater Scrying - Watch what's going on whenever you want.
Simulacrum - Get a single sample of a rare creature, and you can have a near perfect duplicate that cooperates with you completely.
Control Weather - Don't feel like rain? No problem!
Reverse Gravity - Many uses, both practical, experimental, and comedic.
6th Level:
Planar Binding - Same reason as Greater Planar Binding.
Wall of Iron - Instant raw materials, especially when combined with Fabricate.
Legend Lore - For obvious reasons.
Freezing Sphere - Ice was hard to get before refrigeration, but not for you.
Permanent / Programmed Image - With a month or so to kill, you could build a whole illusory town. At the very least, you can spruce up your tower with this.
Shadow Walk - If you need to transport a larger group than Teleport does.
Control Water / Disintegrate / Move Earth - A great aid in construction projects.
Mass Stat Buffs - Need your assistants to be a lot more capable, without extra training or expensive items?[/sblock]
Going beyond that, 5th level gives you Contact Other Plane, a staple of diviners, depending on how risky you feel like being.
8th Level:
Greater Planar Binding - Extraplanar creatures can serve as a source of information or useful powers, not just combat aids.
Discern Location - Find where anything is, no matter what.
Prying Eyes - Allows you not only to scout faster, but also research faster and/or observe an experiment from multiple directions.
Telekinetic Sphere - Easily move large objects, contain dangerous materials, etc.
Polymorph any Object - Too many uses to even count.
7th Level:
Mordenkainen's Magnificent Mansion - Live large, even in the most crowded city or the most desolate wasteland, for one spell slot a day.
Greater Teleport - Travel safely in seconds.
Greater Scrying - Watch what's going on whenever you want.
Simulacrum - Get a single sample of a rare creature, and you can have a near perfect duplicate that cooperates with you completely.
Control Weather - Don't feel like rain? No problem!
Reverse Gravity - Many uses, both practical, experimental, and comedic.
6th Level:
Planar Binding - Same reason as Greater Planar Binding.
Wall of Iron - Instant raw materials, especially when combined with Fabricate.
Legend Lore - For obvious reasons.
Freezing Sphere - Ice was hard to get before refrigeration, but not for you.
Permanent / Programmed Image - With a month or so to kill, you could build a whole illusory town. At the very least, you can spruce up your tower with this.
Shadow Walk - If you need to transport a larger group than Teleport does.
Control Water / Disintegrate / Move Earth - A great aid in construction projects.
Mass Stat Buffs - Need your assistants to be a lot more capable, without extra training or expensive items?[/sblock]
Going beyond that, 5th level gives you Contact Other Plane, a staple of diviners, depending on how risky you feel like being.