I am lucky enough to have a Laserjet 4050 Duplex at home, and I don't ever remember it jamming!
At work, all the printers are Laserjets (2300 now, I think) and again I rarely (if ever) see jams.
Things to check:
Where abouts is the jam? Paper pickup (before the image is applied) or after (at the fuser)?
Are you using OEM are remaunfactured cartridges? Is your paper weight and type within manfr. recommendations?
Are you overfilling the paper tray?
Have you used any adhesive labels that might have left a residue?
One of the most common problems is when the pickup rollers get worn, and more than one sheet gets fed. You would need to get the pickup rollers replaced, although sometimes a good cleaning can cure the problem.