Elvish Mystic & Llanowar Elves - Early mana ramp and nice 1-drops.  They pay for themselves in devotion and mana ramp, plus empower the Elvish Archdruids. 
Elvish Archdruid - mana ramp and devotion, buffs other elves so they arent as weak
Kitchen Finks - chump blockers that gain you life.  Can also be used for agro, plus they provide devotion.
Karametra's Acolyte - great mana producing souce, is not that squishy
Primalcrux - massive creature that provides huge devotion. 
Khalni Hydra - massive creature I can often drop for nearly free that provides devotion. 
Ulamog, the Infinite Gyre & Emrakul the Aeons Torn - win condition; I cannot be milled out
Sylvian Scrying - search for Nykthos, Shrine to Nyx or Boseiju, Who Shelters All
Genesis Wave - win condition; massively plays my deck out, so that I have huge number of creatures and large amounts of mana. 
Tooth and Nail - helps create win conditions, easy to play by 3rd/4th turn for Emrakul, the Aeons Torn or others
Coat of Arms - buffs all of my elves for massive full swing wins
Garruk Wildspeaker - creates mana production combos with untapping Nykthos, Shrine to Nyx; creates chump blockers in form of 3/3 beasts; full swing with -4 ability and elves for a win.
Boseiju, Who Shelters All - Genesis Wave cannot be countered now, neither can my Tooth and Nail
16 Forest - plenty of mana given my other mana production sources
Nykthos, Shrine to Nyx - massive mana production, staple of this deck.  combos with other items in this deck , or you can tap one Nykthos, Shirne to Nyx then play another and tap the second one for double the mana. 

Ghost Quater -  anti-Tron deck things.  You play your special land? Nope, I kill.  Can be searched for if needed through Sylvan Scrying
Wrap in Vigor - anti-Pyroclasm, or any other mass-target spell.  Saves my elves from mass extinction or boardwipes. 
Witchbane Orb - counters burn decks
Asceticism - counters burn decks, allows for 1G regeneration
Oversoul of Dusk - replacement for Primalcrux against decks who will target my devotion creatures (pro RBU)
Utopia Sprawl & Strangleroot Geist & Primal Command - maybeboard items.  Not sure if they have a place in my deck, or where.