I have a USB Garmin GPS18 with the mapping software that came with it. It's good enough for me, never had too many problems.
My system clock is garbage, and I found that
GPSGate Express will work with
GPSTime to update my clock on boot and every so often. But I was wondering, since I'll be able to make virtual NMEA-compatible GPSes now, what other cool software would be worth having?