Urza's Armor -- Okay it is six mana, but for just six damage it reduces all damage by 1. It combos with so many things and beats many a weenie deck by itself.
Arcane Laboratory -- It would be higher but it is just too easy to use, can you say Forbid?
Noetic Scales -- How can we make hand destruction good? Well it could return all creatures to a players hand.
Goblin Lackey -- This is as high as a creature can get in Boldovian terms. There is a deck where the unblocked lackey turns into a Flunkie and an Okk and then turn 3 Ball Lightning -- thank you good game.
Steam Blast -- It is not everyday a set has a red card I like and this has 2. Steam blast should read "kill all creatures" as in the tournament environment this is what it does. Then, let's damage the players too.
Congregate -- In sealed or booster these read gain 20 life and live a dozen more turns.
Purging Scythe -- The ultimate creature controller. Raid in a can for those annoying attacking things.
Stroke of Genius -- Drawing cards as an instant is perhaps the only thing better than controlling creatures.
Mishra's Helix -- No, I was wrong. Controlling land is even better.
Energy Field-- Abusable in many ways. It helps you set up, saves you time, and can lock. What more do you want in a card?
Honorable mention: Dark Hatchling, Prietess of Titiania, Claws of Gix, Turnabout, any embrase, Dragon Blood, Sanctum Custodian, Victemize, Shivan Gorge, Thran Quary, Karn, Umbilicus, Persecute, Sleeper Agent, Time Spiral, Endless Wurm, Brand, Sneak Attack, Worship, and Pariah.
This is a great Boldo set and, at $2.50 a booster at Boldo's, it is a great deal. The biggest minus about the set is the new Tournament Box instead of a starter. For a Dollar more you get 2 common, 1 uncommon and some land. Big deal.