In the end of Puella Magi Madoka Magica, Madoka herself is seen appearing before magical girls whose soul gems are about to be corrupted and taking the gems with her, enabling them to die peacefully and go to the afterlife without becoming witches.In Kamichu!, Death is a rather friendly, if somewhat eccentric goddess, who even once had an affair with Poverty.The Arbiters of Death Parade meet recently deceased humans to determine whether their souls should go back into the cycle of Reincarnation or into the Void, but are usually rather pleasant individuals to deal with, albeit with occasional hints of how how utterly alien their minds are compared to humans.Gelus and later Rem saved Misa's life but were both killed because Shinigami can never use their powers to prolong the lifespan of mortals, and after knowing and hanging out with Light for so many years, Ryuk was all too happy to kill him as soon as he stopped being entertaining. In spite of their pleasant nature, Shinigami will never be "good" as it's understood by humans. Two Shinigami fell in love with a human and used their powers to extend her life. At the same time, they're not all bad - Ryuk really seems to enjoy hanging out with Light and often spends time doing goofy stuff like playing video games in his room. Shinigami have Blue-and-Orange Morality and most don't give humans and their lives very much thought. Death in Gregory Horror Show is the only character shown to be completely friendly to the trapped guests, speaking kindly and offering to help where he can.Momo in Ballad of a Shinigami is a sweet, white-haired girl who not only makes your death painless, she helps the people you are leaving behind by comforting them.When we show fear it jumps at us faster than light, but if we do not show fear, it casts its eye upon us gently, and guides us into infinity." The idea is alluded to in Cowboy Bebop, where Laughing Bull says "Do not fear death.In the end, death is necessary for progression. A world of immortality does sound like a good idea on paper, but when one stops and really think about it, a world of immortality would have no need to grow and advance. The final Big Bad, Yhwach, is written to be the embodiment of the fear of death, and is a perfect demonstration of how far a person is willing to go to escape death. Death is indeed a scary thing, but it will happen to all of us eventually, so we might as well accept it. This is arguably the overarching theme of the series.
In other words, shinigami are portrayed the same way humans are portrayed: as individuals with their own personalities, worries, fears, foibles, strengths and weaknesses. Their role is to guide the dead to Soul Society, cleanse hollows of post-death sin so they too can be guided to Soul Society and also to maintain the balance of souls across different worlds. However, shinigami aren't enemies of humanity even if their focus on the big picture can make them seem aloof at times. Thus, the shinigami are just like humans: they can be friendly, moody, supportive, scary, hostile depending on situation or individual personality type. The fact that the main character becomes one while still alive is a plot point before the Big Bad shows his face. Any deceased human with enough spiritual energy can become a shinigami.