We have an iPad 3 and an iPad 4 and they almost never crash. We gifted our old iPad 1's to relatives when we upgraded a couple of years ago and they have not experienced major problems with this either — perhaps an occasional crash at worst.
(This issue still mystifies me becasuse for a short period after upgrading my iPad 1 to iOS v5, my old iPad did start crashing. But I reinstalled the OS and all Apps from scratch just once and the problem disappeared. A few months later, I upgraded to the aforementioned iPad 3, reformatted the old device and sent it off to my sister who still uses it today).
I still think this an odd and limited combination of hardware/software and Apps used or Web sites visited. While this thread is lengthy and old, my sense is that a relatively small number of owners are affected by this crashing. I also
believe it is likely that the anecdotes and numbers have been inflated by Google and Samsung shills posting fake complaints here. Samsung is a company that engages in questionable business and marketing ethics and it has done things like this elsewhere online.
This does not provide relief to anyone who genuinely has encountered this vexing and frustrating problem, but it does offer an alternative narrative and possie explanations for the inexplicably random nature of the reports.
Personally, I would not hesitate to upgrade. At some point you have to move on. Technology passed by the iPad 1 long ago. While you could switch to an Android or Windows device, they each have their own significanct software, security and/or ecosystem problems that will be frustrating too. Don't get me started on Androids tablet Apps, most of which are just fuzzy, scaled up phone Apps.