Avacyn's Seven Sacred Stars (EDH / Commander)

My take on Avacyn :)

This is a rather slow control deck with a heavy Angel Tribal theme. In no way is it competitive but it is definitely strong and 'fun' for casual games.
Your first goal is to ramp up with cards such as Sol Ring, Mind Stone, Worn Powerstone or Knight of the White Orchid, then Hedron Archive, Solemn Simulacrum and Caged Sun later into the game.
Smothering Tithe is a really awesome Enchantment that has a lot of potential, allowing you to either tax mana from your opponents or stack Treasure Tokens for some explosive turns.
Pearl Medallion, Oketra's Monument, Herald's Horn and Urza's Incubator are here to decrease the cost of your spells and angels in particular. Additionally, Herald's Horn will draw you an extra card at the beginning of your turn if the top card of your library is an Angel. In the same fashion, The Immortal Sun will give you cost reduction, card draw, creature boost AND will make all Planeswalkers cry, but at a greater cost.
Weathered Wayfarer, Land Tax, Oreskos Explorer and Endless Horizons ensure you get a land drop every single turn. Endless Horizons is huge especially late game when you can just exile all of your Plains and draw into your spells without the fear of getting a basic land one fourth of the time. Early game though, limit yourself to exiling between 5 and 10 Plains only, so that destroying Endless Horizons seems less worth it (and handicaps you less in case it does get destroyed).

Next, develop your board with some creatures, survive by using single target removal (Swords to Plowshares and co.), by deterring opponents to attack you (Archangel of Tithes, Kor Haven), or by playing board wipes. Keep in mind that the more you mess with your opponents, the more likely you are to become their number one target, which would obviously be bad. So take action only when it is absolutely required!
Reload your hand with Mind Stone, Hedron Archive, or Arch of Orazca if you're really desperate.
I'm currently trying Dawn of Hope as a draw engine. It works far better in a Lyra deck but has some potential in here too, given the underlying Lifegain theme (Seraph Sanctuary, Angelic Skirmisher, Archangel of Thune, Baneslayer Angel, Gisela, the Broken Blade, Lyra Dawnbringer, Resplendent Angel and the new Sephara, Sky's Blade can get you a ton of life!). Worst case scenario, Dawn of Hope is another Arch of Orazca (6 mana to draw a card) that can block one attacker with a token and gives you 1 Life.
I'm also trying Sensei's Divining Top to filter the top of library and get better draws; it is also extremely cheap and very hard to remove (as you can put it on the top of your library for no cost at all). The Top replaces Mind's Eye, which can draw lots of cards but is really costly.

Once you're comfortable, drop Avacyn, Angel of Hope and protect her via Swiftfoot Boots, Mother of Runes, Adarkar Valkyrie, Grand Abolisher or Endless Sands (but beware of Land destruction, I don't think you will be able to put Avacyn back into the Command Zone if she is exiled with Endless Sands and it gets destroyed!).
Unless things went horribly wrong, you should reach a moment where you are able to cast a board wipe with Avacyn by your side for a massive swing.
One of the dirtiest combos you may want to achieve is to do this every single turn with Nevinyrral's Disk or, even worse, Worldslayer, which would probably result in all your opponents conceding.
I managed to get Vedalken Orrery into the deck in order to play board wipes at instant speed, during the End Step before your turn, or in response to someone exiling Avacyn for instance. You could even cast Avacyn in response to someone casting their own board wipe or trying to destroy the Orrery! As long as you keep some mana open and a few cards in hand, the sole threat of you wiping the board in response to something should deter your opponents from messing with you too much. This card opens a ton of possibilities and is hands down the best enabler in this deck.

Remember: as a slow deck, politics are your best chance to win! Kor Haven can protect you but also an opponent from an attack; Homeward Path can help everyone gain control of their stuff again. Use these cards to strike deals with other players!

Note: This list runs Armageddon, a card that can and will make your opponents really salty, so you'd better ask if they allow you to run the card before the game begins.
If you wish to keep your friends, swap it with something less broken.
My go-to replacement for Armageddon is another board wipe card such as Rout (to play at instant speed), Fumigate, Day of Judgment or Cleansing Nova.

Good luck and have fun! :)