I can’t speak for iphones specifically, but I purchased a Peel case from the guys at Need/Want for my Pixel 2 and it has worked well for my purposes. I wouldn’t say it’s the best case in the world, but I’d recommend it for $25.
Aesthetically, it’s super-minimal and has no branding on it. Additionally, it’s thin and barely adds any height, width or depth to the phone.
On the other hand it doesn’t feel like the most bullet-proof case. I tend to be careful with my phones. Drops are pretty rare and bought the case mostly to prevent scratches. If you tend to be hard on your phones, this may not be the best option.
I bought a TUDIA case for my Moto G, which I mentioned in my review. It was cheap and has worked well for me. There’s probably more aesthetic options out there though.