To this day, I make a point of including a fair amount of double star viewing nearly every time I go out to observe. A night at the eyepiece just doesn’t seem complete without them. I have far too many favorites to list, but they include Albireo (still!), Iota Cancri, Rigel, the Double-Double in Lyra (of course), 18 Geminorum, Struve 2398, and many, many others too numerous to list… including this month's recommendation - Gamma Andromedae (a.k.a., Almaak, or even Almach).
Almaak is ridiculously easy to find in the night sky. Start with the star Alpheratz at the upper left corner of the Great Square of Pegasus. The constellation of Andromeda extends outward from that point, looking (to my eyes, at least) like a somewhat bent cone (see illustration).
There are other (apparently) green stars out there, but this is the most striking example.