This Standard-format deck focused on the Simic's evolve mechanic, and seeks to abuse counters as much as possible - it also happens to include the new Garruk, since he fits in well with any creature-heavy green deck. The cards in this deck are strongly interwoven to create many different powerful combos.
Note that I have not included any Innistrad cards, as they are about to be cycled out - which is a shame, because Predator Ooze is amazing. I can only hope for a reprint, or else something equally amazing from Theros.
The deck starts with obvious Simic 1-drops: Cloudfin Raptor and Experiment One, both bread-and-butter summons for any Simic deck. The latter happens to make a great blocker once he starts acquiring counters, while the Cloudfin Raptor can whittle at your opponent early on, hopefully before he has a way to handle fliers.
There is also Deathrite Shaman, which is specifically meant to help protect the deck from decks that heavily mill (assuming you get lucky enough to draw it). Easy to sideboard if not needed.
Then there are the 2-drops: the Gyre Sage and the Zameck Guildmage. Both cards are meant to help with simple economics: mana pool, and drawing cards.
The Gyre Sage simply helps with your mana pool. As a result, I only have 20 lands, instead of 24.
The Guildmage, of course, also helps you bring in weaker creatures a bit stronger than they otherwise would be, if they arrive late to the party.
Don't underestimate the Guildmage's second ability just because you have to remove counters. Sometimes you desperately need to draw a card - and other times, removing a counter can actually yield some interesting plays. The only real drawback is the mana cost attached to the abilities, with each card draw costing two mana and a counter.
There is also a 2-drop Scavenging Ooze. If you feel you need another 2-drop creature, or just more creatures in general, he is good to swap in for Predator's Rapport, since the Scavenging Ooze heals you for exiling creatures from graveyards. He also works well against any decks that need to use cards from the graveyard, or simply put a lot in there - Golgari, Dimir, Gruul, and more.
Now the 3-drops: Renegade Krasis, and Vorel of the Hull Clade.
The Renegade Krasis is one piece of your two-part counter engine. When combined with Ooze Flux, you can consistently add counters to your entire army, while simultaneously amassing a larger army through creature tokens. The trick is to try to generate at least a 3/3 ooze, which is the minimum needed to evolve a Renegade Krasis with no counters - and you can always take those counters off.
Vorel of the Hull Clade helps you to simply abuse counters more by doubling one creature's counters each turn - it adds up over time, and many opponents underestimate it. I consider him superior to Zegana, and at half the mana cost.
Of the 4-drops, I chose Crowned Ceratok, Fathom Mage, and Bred for the Hunt.
The latter two are obviously meant to take advantage of your counter play to help you draw cards.
Crowned Ceratok is just meant to give everybody with counters trample, which works out very well with Bred for the Hunt.
There is also Corpsejack Menace in this deck - a splash of black. If you get to play him on the field, this doubles your counter generation, which can add up quickly. Both of them on the field will triple your counter generation!
The Kalonian Hydra is the icing on the cake - not necessary to victory, but a powerful trump card, if the opponent can't remove him. It doesn't take many more turns to win, once you play this baby. He's surprisingly powerful for a 5-drop. When he first attacks he becomes an 8/8, but he can still be destroyed - best to get Alpha Authority on him quickly. If you have Corpsejack Menace out when you play the Kalonian Hydra, he enters with 8 counters! And then when the Hydra attacks next turn, he goes straight from 8/8 to 24/24!
There is, as well, the Planeswalker in this deck: The new M14 Core Garruk, which is amazing at bringing out your creatures onto the field - as well as simply finding the creatures you want. He costs 6 mana - but the best time to find more creatures is about when your hand is lacking them.
All of these creatures, unfortunately, limits your spell selection dramatically - even more if you were to have more lands. You have to choose carefully what you need. The trick is to survive until you can amass a decent field.
That's where the sideboard comes into play - Pick what you need based on what your opponent can do. I put in Tablet of the Guilds as an alternative choice to Predator's Rapport (essentially constant healing vs burst healing). I also included Death's Presence as an alternative choice to Primeval Bounty (or hell, maybe you want to include both). There is even Rapid Hybridization, which is great at taking out truly dangerous creatures (Ex: Consuming Aberration).
Admittedly, with how I have designed the deck at this point, choosing what to swap out for the sideboard becomes a very difficult choice. It all depends on your opponent, and what is possible to go without.
One fun trick I like to use: Forced Adaptation and Alpha Authority on an Experiment One quickly creates a creature that is almost impossible to remove from the field of play.