Green and White Control Deck
The name of this deck isn't aggro, but to build layers of defenses quickly, protecting you and your permanents. Think of this as a Chess deck.
That's not to say this deck isn't capable of being on the offensive, but it's more fun to let your opponents get more frustrated with each passing turn as your defenses layer to protect each other and you. (This frustration should be enjoyable - looking for and finding cracks in a defense is appealing to many players - much like Chess.)
[UPDATE: Now FASTER and more awesome with Thousand-Year Elixir on tap!]
[UPDATE #2: Hold on to your seats, folks, as it just got real up in here with the addition of Magewright's Stone! Oh, hell yeah!]
Each game dictates the process, but first try to get the mana and the protection for Captain Sisay, and the legendary permanents you'll bring out.
If you are able to get an Elvish Piper, then you are in fantastic shape - if you can protect it. This means the first Legendary permanent you should go find with Captain Sisay's ability is Rune-Tail, Kitsune Descendent, which is castable for {2}{W}; since your life should (hopefully) still be above 30, you can flip Rune-Tail around to become an enchantment. Rune-Tail won't protect itself or Quicksilver Amulet, but it should protect the legendary creatures coming in from being destroyed by most methods. That way you can cast your Elvish Piper and have a good chance it'll still be there your next turn.
If you get the Quicksilver Amulet, and it manages to survive another round, get Avacyn, Angel of Hope in your hand using Sisay during your next turn, then get her out - you'll pay four mana and tap Quicksilver Amulet letting Avacyn hit the battlefield. After your untap step, the only way for someone to actually prevent you from getting Avacyn out is to remove her or your entire hand either by forcing you to discard or exile her or your hand, all in response to you putting the activated ability on the stack. Once Avacyn is on the battlefield, permanents you control are only vulnerable to exile, spells that target you, and reducing to zero or below the toughness of your creatures.
Then, get Sigarda out using Captain Sisay and either the Elvish Piper or the Quicksilver Amulet, or try to hard cast her and hope no one has a counterspell. Once she's out, the only thing you'll be vulnerable to is exile. However, since there is plenty of hexproof going on in this deck, hopefully you'll come across one before long, making anything short of mass exile or targeting you will be able to affect much of your board at all. Naturally, once you also get Witchbane Orb, Wheel of Sun and Moon, Pariah on Cho--Manno or Stuffy Doll, and overlapping hexproof, as long as someone doesn't break out a Glaring Spotlight or Archetype of Endurance, you should be practically untouchable.
The pieces are all here, most are duplicated, and barring a few different WIN-CONs or global effects, you can get to the point of just sitting back and biding your time.
Of course, if you really want to be very unkillable, get a Platinum Angel.