Both accentuate arses quite well. Yoga pants/leggings always have that chance of being see through, however for me the best thing is the occasional peek of underwear at the back of low rise jeans. I love the feeling of anticipation whenever my girlfriend goes out wearing a pair of jeans and she sits down or bends over revealing a bit of what's underneath to anyone around.

Definitely low rise jeans. It always made my day when I saw some buttcrack or hanes panties.

It may be weird but somehow tight yoga pants that show the contour of a pair of cheeks seems more exposed than a little crack. Sometimes I have to pinch myself that this is the style these days. And full ass exposure at the beach and pool. What a time to be alive.

Both
 

Low rise for the whaletales

yoga pants for the thong prints

Yoga Pants
 

I definitely go for yoga pants.
The right ones. Real tight, a bit see through, great camel toe. For me nothing can beat this.
My wife has some that show her pussy so nice.
For example this one.
That shorts she wore almost every day on our vacation.
Sometimes when I went away, there were gatherings of man behind her. Some had their phones out, obviously taking pics. I hoped, I would find those pics later in the internet. Since it did not happen, I guess I have to help..
So how do you like this revealing leggings on my 26 year old sl*t wife?