There are some franchises that I wish was still continuing as well:
No One Lives Forever - this spy-them-up set in a 60's time frame was brilliant. The sequel to the game was even better. Both these games sit with a Metacritic rating of over 90% on PC. The spin-off title that followed as a prequel was so bad that it pretty much killed the series completely. I wish this series got a proper reboot or a remaster. I loved this game a lot.
Project Gotham Racing - This game was one of the fist games I played on my Xbox 360, and it blew me away. Although these days we are getting more and more different racing games that pretty much do the same as PGR, with Forza being the spiritual successor of the franchise, it would be awesome to see a revitalizing of the old franchise.
Commandos - Why the hell did they stop this franchise. It was a brutal game of strategy and stress, forcing you to think and replay many sections of the game. I'm pretty sure there are much more that can be done with the franchise, and there are many more setting for it to be featured in.
Warcraft - Yes, I'm saying it has died. I don't see this franchise being restarted any time soon, though it is a sin for it to die like this. I hope that I'm wrong and that one of these days we will get the long awaited Warcraft 4. Warcraft 2: Tides of Darkness still ranks up as one of my all time favourite games.
Age Of Empires - Although there has been some remasters and such in the near past, the franchise has probably died off complete, which is a shame. AoE has a very special place in my heart and will forever remain there. I would so love to get a new game to go WHOLOLOLO in.