A proper sequel to Simcity 4. I've have about 60 hours in Cities: Skylines, but for me that's nothing compared to Simcity 4 or Simcity 3000 or even Simcity 2000 (still play it occasionally, but not as much as 3000 and 4).

Cities in Motion 3 - This will never get released as Colossal Order have switched their focus to Cities: Skylines. Cities in Motion 1 in particular had a unique atmosphere.

Team Fortress 3 - Without all the random weapons in TF2.

HL3 - No comment on this one.

Simgolf - There are a couple of newer golf club management games, but I would prefer a modern isometric take with the same whimsical vibe like in Simgolf.

Leisure Suite Larry 8 - Made by Al Lowe, perhaps based on the unreleased concept from the late 90s.

Arcanum 2 - With good combat.