@JamesK's answer indicates that HiRise is the "highest resolution camera on a Mars orbiter" but it's worth noting that it is also (at least currently) the highest resolution known, human-built camera anywhere in deep space!
@Phiteros' answer to What's the largest aperture telescope sent beyond the Earth-Moon system? begins:
After looking through ...
The highest resolution images come from the HiRISE camera on the Mars Reconnaissance Orbiter. With an angular resolution of one micro-radian it has a ground resolution of about 0.3 m (12 inches)
Here's an image of the Phoenix lander on its parachute, at a resolution of about 30cm taken from https://static.uahirise.org/images/2008/details/cut/...
The answer is on this National Geographic page about the best pictures from NASA's official photographer Bill Ingalls:
If you love space, odds are you’ve admired the work of Bill Ingalls.
He has been NASA’s senior contract photographer for 30 years, a job
that has taken him across the world—but not yet beyond it—to cover
major moments in space exploration.