Play-Doh can be a lot of fun, but it's also great to mix it up and do different stuff with it.
A fun thing I liked to do with play-doh was turn it into edible play doh, seeing as my boys loved trying to eat it when they were under the age of four. You can look up recipes online, make the play-doh and then make a Play-Doh Cafe, with food made from play-doh that your children can eat. My boys loved this.
Make animals out of playdoh. Try and create a large zoo and get the kids to make animals. Give everyone a list to see if they can make all the animals with the play-doh. Make it funny and put "half cat half fish" or something like that on the list.
Make bowling pins and a bowling ball from play-doh. Play-doh bowling can get tricky, but it's fun.
Get in the kitchen and make your own play-doh. Let the kids get their hands dirty and choose their own colours.
Buy 50 cent play-doh packages from your local toy store, and let the kids be creative with it. Use it outdoors, at the table or on the concrete. You can even put the play-doh in a kiln and make little statues.