Ardent Recruit

Metalcraft — Ardent Recruit gets +2/+2 as long as you control three or more artifacts.

Bladegraft Aspirant

Menace
Equipment spells you cast cost {1} less to cast.
Activated abilities of Equipment you control that target Bladegraft Aspirant cost {1} less to activate.

Goblin Gaveleer

Trample
Goblin Gaveleer gets +2/+0 for each Equipment attached to it.

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Leather Armor

Equipped creature gets +0/+1 and has ward {1}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {0}. Activate only once each turn.

Mountain

Sunspear Shikari

As long as Sunspear Shikari is equipped, it has first strike and lifelink.

Flayer Husk

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Equip {2}

Golem-Skin Gauntlets

Equipped creature gets +1/+0 for each Equipment attached to it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery. This card enters the battlefield unattached and stays on the battlefield if the creature leaves.)

Ancient Den

Plains

Barbed Batterfist

For Mirrodin! (When this Equipment enters the battlefield, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature gets +1/-1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)