In my almost 19 years I've found my perfect pair of jeans only last summer. Everyone's body is different and that does need to be taken into consideration when picking jeans but I'm going to talk about a few places that are generally really good or good for a specific body type.
My favorite place to buy jeans is Old Navy. My body gains weight equally everywhere, and I have an hourglass/pear figure and I'm 5'5 and both my pair of Old Navy jeans fit my waist really well and reach my ankle perfectly too! They have amazing stretch to them and the store has frequent sales where the jeans are as low as 15 dollars! The fabric is also a nice thickness that makes it durable but also breathable.
I also have tried American Eagle Jeans and they look really good on but they are restrictive and don't allow me the space to eat a lot. They are also the only pair of jeans that had the belt holding strap on the waist rip off. They are around 50 dollars but I got mine on sale for 30 dollars. Though they didn't work the best for me, my friend who is really tall and skinny lives by them! She only wears American Eagle jeans and they fit her lean body really well! So if you're a slim gal American Eagle is the place for you!
Now I have never personally tried Fashion Nova jeans but they are marketed to women with a curvy figure. And I have watched many reviews on YouTube and they rave about the fit and comfort of these jeans. They are also really affordable so for all those curvy girls, Fashion Nova might be your new favorite.
The best way to find your perfect pair of jeans is to go out and try some on! I wish you luck on your jean shopping ventures!