M&M series:
Might and Magic 6-Pack Limited Edition (includes MM 1, 2, 3, 4, 5, 6) $2.49
Might and Magic 7: For Blood and Honor $1.49
Might and Magic 8: Day of the Destroyer $1.49
Might and Magic 9 $1.49
HOMM series
Heroes of Might and Magic $2.49
Heroes of Might and Magic 2 Gold $2.49
Heroes of Might and Magic 3: Complete $2.49
More:
Far Cry: $3.99
Far Cry 2: $3.99
and 40 more titles.
https://www.gog.com/promo/20191204_midweek_sale_ubisoft
Update:
Some other worth mentioning titles:
Brothers in Arms: Earned in Blood $2.49
Brothers in Arms: Hell's Highway $2.49
Brothers in Arms: Road to Hill 30 $2.49
Heroes Chronicles: All Chapters $3.39
Rayman series: mostly $2.99
Might and Magic 6-Pack Limited Edition (includes MM 1, 2, 3, 4, 5, 6) $2.49
Might and Magic 7: For Blood and Honor $1.49
Might and Magic 8: Day of the Destroyer $1.49
Might and Magic 9 $1.49
HOMM series
Heroes of Might and Magic $2.49
Heroes of Might and Magic 2 Gold $2.49
Heroes of Might and Magic 3: Complete $2.49
More:
Far Cry: $3.99
Far Cry 2: $3.99
and 40 more titles.
https://www.gog.com/promo/20191204_midweek_sale_ubisoft
Update:
Some other worth mentioning titles:
Brothers in Arms: Earned in Blood $2.49
Brothers in Arms: Hell's Highway $2.49
Brothers in Arms: Road to Hill 30 $2.49
Heroes Chronicles: All Chapters $3.39
Rayman series: mostly $2.99