Here are a few that are surprisingly robust: Bazaar of Baghdad - $2470 Volcanic Island - $535 Underground Sea - $505 Tropical Island - $480 Eureka - $480 Mox Diamond - $420 Bayou - $355 Tundra - $325 A couple of the non-blue Dual Lands also show up on the hotlist, as does Gilded Drake, Sliver Queen, and Grim Monolith
Similar to Walking Ballista, Marketback Walker enters with counters equal to half the mana you pour into it and can gain additional counters for four mana
This gem from the Unbroken Bonds expansion set is a shining example of Dark-type Greninja in action
Drop her on turn three, make two 1/1 hasties, swing, keep all of the loyalty on your leader
Whether this is playable in Standard or not really depends on whether we get a good one-drop Otter
(Even the empty cardboard box that once contained the cards goes for over $200!) And the reason why is that a Gold Star Charizard in perfect condition, such that it receives a PSA grading of 10, is currently valued at over $58,000