A good recliner should let your shoulders drop the second you sit down, before you've even found the lever. The best ones have a footrest that glides out smooth and quiet, not that jerky lurch that makes you feel like you're being launched out of a chair rather than settling into one, and the back should hold you at an angle where you could actually fall asleep without your neck complaining about it the next morning.
In an ordinary room, a recliner works best when it doesn't try to be the main event. Next to a regular sofa, or across from one with a small side table and a lamp within reach, it reads as a proper chair rather than a piece of medical equipment someone wheeled in. I've seen them paired with a low bookshelf and a rug underneath to ground the whole thing, which helps, because a recliner on its own in a corner can look a little stranded, like it's waiting for its own room.
On color, I'd steer away from anything too shiny or too pale. A stain shows up fast on light fabric, and leatherette in a bright white looks sharp for about a month before it yellows at the headrest where everyone's hair touches it. Deep neutrals hold up better, a charcoal, a worn looking brown, a muted green, something that doesn't flinch at a coffee ring or a dog deciding it's his spot now. Fabric with a bit of texture to it hides more than a flat weave does, and it's forgiving when the cushion compresses a little unevenly after a year of being the favorite seat in the house.
These chairs earn their spot in rooms where someone actually stays put for a while, a den, a reading corner, a spare bedroom that doubles as a place to recover from a cold. They make the most sense in colder months, when the idea of sinking down and not moving for two hours sounds like the whole point of the evening, though a good one works just as well through a slow summer afternoon with a fan running. Houses with more than one regular sitter benefit from having two, honestly, because one good recliner in a shared room tends to start arguments about whose turn it is.
What surprises people is how a recliner ages differently from other seating. The mechanism gets looser and easier with use instead of tighter, the leather or fabric softens into the shape of whoever sits there most, and after enough years it stops looking like a showroom chair and starts looking like a chair that belongs to someone specific, which is really the point.