I like Roller Coaster Tycoon. I find that Railroad Tycoon is a bit confusing, though. Different company, different rules. Not all Tycoon games are from the same developers.
For girls, I would recommend the Nancy Drew PC games. They’re pretty clean, and could be appropriate for a Jewish home with a few exceptions: one game covers Mayan culture, another has heavy Greek mythology themes, one game takes place in Ireland and you can see some Celtic crosses in the background of one scene and a couple of the games have particularly intense ghosts (that turn out to be fake in the end). Oh yeah, and Nancy does have a boyfriend and is often a character Nancy can call on her in-game phone for game hints, but that’s not a major part of the games and you can easily play them without having to bring that up at all. There are about 30 games in the series now, and it’s at the parent’s discretion to determine which ones are suitable for their homes.
There used to be a series of Jewish games about the Shoftim called Tanach Quest. Not sure where to find it anymore, though. It may be a bit disturbing for young players, though, because — believe it or not — there’s a bit of bloody violence and jump scares from villainous characters you have to kill with axes and knives.
You can also use a ROM emulator to play old arcade games like Pacman, Joust, and Paperboy.