Most solid game franchises

[Slimebeast]

Another way to ask "what are your favorite game series".

For me off the top of my head:

Elder Scrolls

Fallout (despite Fallout 4 being a bit weak, it's still solid)

Dark Souls

Dragon Age (despite Inquisition being a bit weak, it's still solid)

Bioshock

XCOM

Divinity

Doom

S.T.A.L.K.E.R.

God ov War