Several years ago I discovered "cargo pants".  I fell in love with them for their ability to carry a lot of stuff.  After a few years of experience, I think I sort of became a connoisseur of pants with many pockets.  The Tru-Spec 24/7 lightweight "tactical" pants fill the bill as my favorites.  Why?  Well, they are made of lightweight rip-stop poly-cotton fabric which is strong, resists fading and stains and is heavy enough for most days year round in my area.  On the hottest days of summer, I wear the shorts equivalent of these pants.  The poly-cotton fabric is almost indestructible but, being mostly polyester, would likely suffer some melting/burning from campfire sparks or errant embers from smoker's noxious tobacco.

The pants are comfortable with an adjustable fit due to the inclusion of a wide elastic slider band in the waistline.  This allows the pants to expand and contract with various movement as well as with fluctuations in the wearer's girth.  There are a lot of pockets on these pants.  The cargo pockets and rear pockets use industrial strength Velcro for closure.  You won't lose what you've put in these pockets if you secure the flap closures.  The cargo pockets are also gusseted so they will expand but lay completely flat when empty (aided by a small Velcro patch).  The front pockets are deep and wide.  Extremely deep and wide.  Big items can fit easily in these pockets.  On each side there are small open top pockets on the thighs that accommodate standard sized pocket knifes or other small tools.  Inside both pants legs are knee pouches that can take knee pads for those times you will be crawling or kneeling on hard surfaces (but no pads come with the pants).

Compared to the 5.11 brand, I've owned both the poly-cotton and 100% cotton models of those.  The all cotton 5.11s shrink over time even with careful laundering.  While the 5.11 poly-cotton pants appear to be made of the same fabric, they are not as comfortable and not as well designed as the Tru-Spec pants.  I currently own 6 or 7 pair of the Tru-Spec pants and I wear them almost every day.  I can't remember the last time I wore a pair of jeans, these pants are so comfortable and so practical.  I highly recommend them.