Since I rent to mostly families I've noticed that the walls get pretty dirty at about six-year-old height and below. ;)

I also noticed the one house I have with wallpaper seems to withstand much more wear and tear than paint.  Even with "good" paint, I typically cannot wash away all of the grime once a renter has left and at least end up repainting common areas. But, even though I hate wallpaper, I have to admit that it cleans up pretty well and even if you don't get everything pristine the pattern tends to hide a lot of damage.

The thing is, good textured wallpaper works best and that stuff tends to be expensive.  Anyone have some alternative wall coverings that aren't much more than paint but are more durable?

Good question @amy e. Simply wash and painting walls works for me.

I agree that paint is the best, as kids and pets can tear or scratch the wallpaper.  But, if you are committed to that option,:

Graham & Brown wallpaper

I believe Lowe's also carries a similar less expensive option.

wash paint with soap and water. even bleach. nothing's cheaper.

semi gloss paint and wet magic erasers can work wonders

Otherwise I've seen corrugated steel panels on walls a few times