Personally, I release the vast majority, but I know as far as crappie anglers are concerned, I'm in a very small minority. I know many anglers who I have great respect for who seem nearly incapable of releasing fish like its irresponsible to release a caught fish.
If I'm fishing with someone who prefers to keep fish I try to make sure they leave with their limit. I give away far more fish than I keep, but that number of fish is a tiny portion of the fish I release.