MTG Salvation

Krenko and the blue untappers are really good together, and can easily net you a ton of goblins all at once (even though they are not instants or sorceries to work with the commander):

• Krenko, Mob Boss
  
• Freed from the Real
  
• Intruder Alarm
  
• Crab Umbra
  
• Pemmin's Aura

Coastal Piracy and Bident of Thassa allow your goblins to fuel your hand.
Opposition turns your masses of goblins into boardstate locking.
Skirk Prospector converts Goblins to mana.
Teleportal pushes them all into the red zone.
Goblin Bombardment provides another alternate wincon.

Goblin Flectomancer protects your boardstate with a Swerve effect (and has an amazing hat).