I like the one with the yoga waistband.  The ones with the regular elastic waistband were nice except for the waistband.  I'm a pretty average size, it's not like I have a giant belly or anything, but I can't tolerate any extended pressure on my stomach.  I was very happy with the plain black leggings with yoga waistband because they stay on without putting too much pressure around my waist.  I also really like the pocket that is sewn into the waist band.  It's a nice deep pocket, I can put a key in there without worrying about it falling out.

The material of the leggings is super soft and the "one size" fits me nicely (I am 5'5" and around 125 pounds.. normally wear inseams around 30").  I like the stretch of the fabric, and it is not see through!

I can't be bothered to hand wash any items, so I threw it in the washing machine along with everything else..  I always wash everything on gentle cycle, with cold water, and then tumble dry low.  It seems to have held up just fine in the wash, although I'm not sure how well it will hold up over time.  If it doesn't last as long as I expect, I'll update my review, but I think it will be fine.