Big Choice
I've been lucky ( or unlucky depending on the program! ) to use all the flight planning programs from Jeppesen, Universal, PPS, etc etc
I must recommend Universals' online system UVflightplanner.com as being supurb. In comparison to the others the weather data is spot on ( ISA devs, temps, winds ) and the package is both intuitive and powerful.
Jeppesen ( Flightstar/Mentor tpye ) I find more hit and miss on the weather data and PPS is sadly just antiquated and unpleasant to use ( although it has improved out of all proportion in the last few updates ).