If I want a drainage system in my dirt crawl space, is french drain
the only choice? I believe they clog up after a number of years,
perhaps between 10 to 20 years.
I need a non clogging drainage system because I also want to install a
vapor barrier that seals the ground as well as the foundation wall. If
the drainage system clogs, I would have to rip the vapor barrier to
repair it.
I'm located in washington state near seattle in case you have region
specific recommendations.

Unless you have a high water table or something that causes the water to
come up from below, your best bet is to steer as much water away from the
foundation as possible.

Install a french drain around the outside perimeter of the foundation. I
used 4" corrugated drain pipe with the slit perforations. Wrap the pipe
with landscaping fabric, or install dedicated "socks" to keep the slits
from clogging. I installed our drain in gravel, and covered it with a
layer of gravel to improve drainage, wrapping everything with landscape
fabric to prevent soil from working it's way into the gravel drainage
layer.

Of course, the french drain should "drain" somewhere, whether that's off
over a hill, or into a drywell away from the house where water can soak in
slowly.

Once the drain is in, make sure your yard slopes away from the house so
surface water isn't directed towards the foundation.

Also, install a good gutter system on your house, and run a separate drain
line to direct the water away from the house. Do not tie the gutter drains
into the french drains, or you might end up sending water towards the
foundation instead of away.

If you have water inside the foundation walls, you'll probably have to
install some kind of interior drain and a sump pump to remove the water
that collects.

Anthony