A game only requires mild success these days to earn itself a sequel or a handful or expansion packs. The majority of the great sim games have gotten sequels. There are just a few that I'd love to see remade with today's technology.
Is there any who has played "Theme Hospital" and not loved it? If there is, I haven't met him. The job was simple. Buy the right equipment, have the right doctors and rooms available at any given time. The illnesses patients contracted kept me in stitches. I don't know how a waiting room full of Elvis impersonators wouldn't have you giggling.
I cannot begin to give you an estimate on the number of hours I spent playing "SimTower." Managing the traffic flow on the elevators was a pain. It was the excitement of seeing residents move in apartments and a demand for businesses that made it worth the effort.
I had an odd obsession with "SimFarm" in the early 90s. Odd because watching crops grow isn't the usual way to spend free time. "SimFarm" wasn't all harvesting and planting crops. Livestock could be raised and sold for cash. Fences needed mending. Machinery needed upgrading. Always something to do on the farm. "SimFarm" made watching pixelated cows and corn being harvested satisfying and addicting.
"Microsoft Train Simulator" brought the fantasy of sitting in the conductor's seat of a train alive. The controls were realistic and not cheesy stop and go controls. Best of all it was quicker and easier to learn than "Microsoft Flight Simulator." I'd love to see what the developers could do with the new 3D graphics technology.