Hello rcflyers. Welcome to the forum.
There are some high end programs and games that can greatly benefit in functionality from being installed and run from the faster SSD. But a lot of the run-of-the-mill will barely change other that loading faster (office programs, browsers, etc.). So for the most part I would keep them on the spinner.
For initial setup of the SSD you could clone the OS from the old spinner to the SSD. If the OS is currently looking for program folders on the 160GB then the switch could be very fast and easy, I wouldn't change a thing.
After all is set up and tested fine then you might consider which programs to uninstall from the 160 and reinstall onto the SSD.