Here are your era choices IMO:
EM
Early solid state
System 11
90s DMD
Modern Era
Era selections depend greatly your bankroll. So figure that out & then purchase accordingly. Rotate them over time. With your limited space, never have 2 games on hand from the same era. Variety is the spice of life, and will make you a better player. When you determine your favorite eras, swap titles routinely from that era.
My tastes are from all different eras, so being limited to 2 pins would lead to some really difficult decisions.
