My standard Golgari/Midrange/Rock Deck. It goes into nearly any matchup with the ability to win. Once I sideboard in cards against a certain matchup it's pretty hard to beat, and the deck is incredibly fun to play as well.

Sylvan Caryatid: Mana Ramp, Hexproof, slows down aggro and control can't kill her unless it's a board wipe.

Lotleth Troll: I love this card. Difficult to deal with regen, has trample, and can grow. I can use him early to get in some trampling damage and late as a chump blocker. And occasionally feed him things to whip out. Never really grows past 3/2. I run him over Scavenging Ooze because he's 10 dollars cheaper and has regen.

Dreg Mangler: Another dual purpose creature. Early on it's 3 damage haste. Later on its food for the troll and then scavenge on Reaper.

Boon Satyr: Above the curve creature that I can flash into a attacker or bestow late game. Kills Blood Baron, which is the main finisher for control decks in my meta.

Vraska The Unseen: Anti Everything planeswalker. Protect's herself alright and takes out jace, Garruk, everything. Normally get's sideboarded out against aggro though as she is a little expensive.

Reaper of the Wilds: The rock. She normally comes down late game at around 6 mana so she can either have hexproof or deathtouch. Doesn't die to Selesnya Charm, Doom Blade, Anger of the Gods, Mizzium Mortars, etc. Deathtouch means they don't want to block her. And the scry works well with Underworld connections.

Removal:

Abrupt Decay: Hit's almost every problem creature in aggro, very good against Selesnya and RDW, even Mono blue devotion. One of the best reasons to run B/G

Putrefy: Murder-Plus. Kills Pithing Needle when they sideboard it in, and most creatures. Can't tell if I should run more of these or Hero's Downfall.

Doom Blade/Devour Flesh/Heros Downfall/Duress: Standard removal suite, all of them get sideboarded around as needed.

Tools:

Underworld Connections: Card advantage is important late game to keep up with control and stay ahead of aggro, scry away what I don't want with Reaper and pick it up with this.

Whip: Lifelink to stay alive late game.