Zoo, grün80 park, minigolf, i liked tinguely museum as a kid, check out events and fairs in the region, visit the region lot of stuff in a 2 hours radius from basel, for rainy days there's transport museum in lucerne, technorama in winterthur and things like that very suitable for families.
If you like pools and depending on the age of the kids look for fun places like Alpamare, or more relaxing thermal baths like bad zurzach, bad schinznach, etc. There is maybe even more in Germany and France.
For more routine stuff biking, hiking, skiing are very common swiss sunday activities, biking is suitable for "lazy" people too, you can rent e-bikes.
If you got money why not weekend trips, the things to do become infinite.
This website can give you some ideas too: http://www.myswitzerland.com/en-ch/home.html