This is the current rotation for standard
Until October 2, 2015:
Theros
Born of the Gods
Journey into Nyx
2015 Core Set
Until early/mid 2016:
Khans of Tarkir
Fate Reforged
Until late 2016:
Dragons of Tarkir
Magic Origins
So based on this, the 2 sets that make the most sense, at least for now are DoT and Origins.
So based on this, the 2 sets that make the most sense, at least for now are DoT and Origins.