Today, Null Rod finally burst. Old Reserved list rare with minimal Legacy, Vintage and Commander application. I called this eventual spike 5 months ago. Trust in Urza!
So continuing the Reserved list specs, let's looks a Tempest's Apocalypse:
This is a no-brainer. Rare in an old set. $2 apiece, no foils. Also, convergence with the Shadows Over Innistrad's return of Madness mechanic.
Go deep. These will spike to $12 within a few weeks, then fall to a minimum of $5, then probably rise again to $12-$20 within a year on the back of Eternal Masters and Madness.
Just believe me, already!