This isn't for sequels you wouldn't mind seeing, but sequels that would have you frothing at the mouth and just throwing money at a cashier while screaming "JUST GIVE ME THE BOX!!!". Make the assumption that the sequel would be the best of the series.

My list:

1. Betrayal in Krondor 2 - Really ANY awesome game set in the Midkemia world that allows for real role playing and immersion. Open world would = see you in 40 years.

2. Baldur's Gate 3 - I don't even care if its set in the same area of the world or even if its in the forgotten coast, I just want a 200+ hour, strategic, endless replay RPG. No, Dragon Age isn't BG3.

3. Dungeon Keeper 3 - nothing like it before, nothing like it since. I preferred the first one, but second is still good.

4. Might and Magic ANYTHING (if it was done by the people that worked on mm6).

5. Age of Mythology 2. My favorite RTS of all time.

6. Mount and Blade: Warband 2 - Just checked my played on this game - 350+ hours.

7. Master of Orion 4

Now for my totally ridiculous dream game so impractical and awesome it could never be built:

CIV IV - with the ability to pause and engage in open world roleplaying at any time and the game transitions to alpha centauri and turns into Master of Orion which can be played as a strategy game and paused for open universe role-playing. Talk about memory leaks!!!