That all depends on your hardware (including device drivers) and the type of video you edit... so there is no one answer
My (somewhat old) computer is described at http://www.pacifier.com/~jtsmith/ADOBE.HTM and, with PrPro 3, I have NEVER had a program crash... but I only edit DV AVI type 2 video files
Editing any type of HD or compressed file is much harder... AVCHD being the worst in terms of hardware requirements
This is aimed at Premiere Pro, but may help
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
And even more hardware discussion http://forums.adobe.com/community/premiere/hardware_forum
Including this post about 3 possible builds http://forums.adobe.com/thread/598040?tstart=0
Work through all of the steps (ideas) listed at http://ppro.wikia.com/wiki/Troubleshooting
If your problem isn't fixed after you follow all of the steps, report back with the DETAILS asked for in the questions at the end of the troubleshooting link
I agree with John T., that it all depends. There are so many variables involved. FWIW, both PrPro 2.0 and PrE 4, are wonderfully stable programs for me. If I had to give points, PrPro would probably win, but then I use it much more often and with much larger Projects, so not sure that my observations are 100% fair, or complete.
Now, with that said, it does seem that PrE 8 (initial release) is much more sensitive to system specs., than previous, but PrE 8.0.1 seems to fix much of that. Also, CS4 PrPro had stability and compatibility issues, but with CS4.2, things seem to have been worked out. Each version suffered from "growing pains."