The Mainactor in the format was and probably still is is Delver.
It is a tempo deck and plays a butt full off cantripsand "tempoish" cards like bounce and counter in combination with
Some played Geist of saint traft(you will see him later) or lingering souls(also later)
Then there was U/B control which is pretty much the definition of Draw-Go control.Mashing some counter and removal.Pretty much nothing that new.
Another "control" was Esper control which was Tap out in style.Getting wrath effect mashing suntitan and playing
To metion is here that not all variants played unburial rites.
Another Deck was still some combination of Primeval ramp.Important cards to note were
in combination with inkmoth nexus.
Another popular archetype was R/G Aggro revolving arround
and swords+ kessig wolf run pretty much.
And there were various Birthing pod midrange decks.
Furthermore there was All kind of tribal human decks.
Honorable mentions go to:
Since m13 is pretty new there probably isn`t a dominant archetype yet but till now Delver was definitively the dominant.
In Legacy Delver and Lingering souls had a big impact aswell.