Tolarian Academy is no doubt the most powerful land ever printed. Especially when you consider all the moxen and ways to untap it using spells like Time Spiral, it's restricted in Vintage, and if it wasn't you see a swarm of super high.tide-style decks with turn 1 kills being the norm.
It's a tough competition to be on the top 10 list, but I'd say it can do it
(0. Contract from Below)
1. Ancestral Recal
2. Black Lotus
3. Yawgmoth's Will
4. Necropotence
5. Sol Ring/Moxen
6. Tolarian Academy
7. Mana Drain/Force of Will
8. Bazaar of Baghdad
9. Mishra's Workshop
10. Tinker
11. Time Vault
12. Time Walk
13. Demonic Tutor/Vampiric Tutor
14. Strip Mine
15. Oath of Druids
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Ours is not to reason why, ours is but to do and die.