Diana barely knows 47 but is willing to risk her burgeoning career with the Agency to (somehow) protect him from Soders' unfairness during the tryouts.
The sequel reveals that she guided him through the ejector seat opportunity.
If you sabotage Dalia's laptop, her secretary, Hailey, has a breakdown where she believes she's going to be killed for her failure, only for the guard on the balcony to agree to protect her and offer to run away with her. It's revealed he's always known she was a spy for Valerie St. Claire but kept it to himself because he loved her. If allowed to run away, they escape Dalia and 47 deals with their enemy chasing them. Of course, you can kill one or both of them.
If you begin, but do not complete, the Opportunity involving the interview with Novikov, you practically ensure an up and coming journalist's career. An interview with a world famous designer mere MINUTES before his death may be the golden goose of fashion journalism. Not to mention the warm and fuzzy feeling you get by making 47 play the role of a kind man just wanting to help out when you give her the camera lens.
A staffer can be found in the locker room having a breakdown over being mistreated by the guests. As she starts crying, her coworker comforts her, even joking about spitting in their champagne to amuse her.
You can give Silvio Caruso a few hits off some apparently very good weed before killing him painlessly.
You can also use expired spaghetti instead of rat poison to poison Silvio's spaghetti, giving him a wonderful blast of nostalgia before you push him off a cliff (granted, his reaction was rather monotone, but it's the only time in the mission where he's contented).
A doctor working on the bioweapon accidentally killed an associate, which has brought home how dangerous the weapon is. She's thus decided to build a device to destroy it remotely. The consequences of this could get her killed but if 47 just knocks her out, he can destroy the virus her way without implicating her.
Kind of related is the client who ordered the hit in the first place. Most clients of 47 order hits due to financial or reputation-related reasons; it's just that their victims happen to be assholes. This client ordered the hit purely on ethical grounds, to stop this super-deadly virus from getting onto the market without harming the company.
In the Landslide bonus mission, sniping Abiatti before he murders Father Francesco grants you a challenge.
While wandering around Marrakesh, you can find a brother and sister pair discussing his ex-girlfriend who is now head of security at the Swedish embassy. They talk at length about his lame but well-intentioned attempts to impress her. This is part of an Opportunity but a reminder all of the people involved in 47's life have their own loves and worries.
On the second floor of the school, there's a soldier who is talking to his daughter on the phone, while leaning out of a window. He mentions her birthday that he couldn't attend due to his job, and promises to buy her a present. As the girl begins to cry as she misses her father, the soldier asks to talk with her mother, who then proceeds to tell something about twins to him. Of course, 47 can pull the guy to his death during, or immediately after the phone call.
In the A House Built On Sand bonus mission, taking out Mendola and Kong during/after their meeting can count as this in a somewhat twisted fashion. While you still have to murder the somewhat sympathetic Frenchman, you got to ensure Kong wires the money to Mendola's bank account, so that his family would still receive the money after his death.
One of the waiters at Kong's party consoles a waitress on the receiving end of Kong's temper.
The Mama Bear and Papa Wolf qualities of Hannah Highmoore's parents. Their daughter killed and the man responsible gets off? They hire the world's greatest assassin to kill her murderer and his lawyer.
Jordan Cross, unlike the vast majority of 47's targets, is genuinely remorseful over his actions. Not enough to turn himself in and pay the consequences of his actions but enough that he comes across as more of a spoiled kid rather than a genuine monster.
Despite his unexcited reaction and subsequent tantrum, it's quite touching to see Jordan's friends do a surprise party for him. After the previous targets portrayed as rude and dismissive of their associates, it's good to see one that gets along with their employees.
Stopping a morgue doctor from committing suicide nets you a challenge.
In a twisted way, the anger that Dr. Laurent feels when realizing that Soders killed his father and made it look like a suicide is heartwarming to a degree. His willingness to forsake his reputation as a surgeon (and his place in history, as Soders had agreed to fast-track FDA approval of Laurent's proprietary stem-cell treatment) to avenge his father shows how much he cared for his old man. (Laurent will remind himself of his oath as a doctor and pledge to complete the surgery, which is equally heartwarming... but will seek a very justified revenge if 47 gets him high.)
In a twisted way, destroying Soders' heart transplant and leaving the mission with him alive, so he can later succumb to heart failure. Rather than brutally murdering him, 47 can show a measure of mercy to his former ICA colleague by letting him pass away in relative peace.
Diana's sympathy towards Soders. She is shown to find the contract regrettable and seems numbed when Soders is killed.
In Patient Zero, if you spared/saved Jeff all three times he appeared, you can find him wandering around the resort. Having survived all his suicide attempts, Jeff has pulled a MookFace Turn and now rejects the cult, even planning a Heroic Suicide in case he gets infected.
The Sarajevo Six target spends the entire mission looking at the distance on the Yoga platform. If he is approached, he recognizes 47 instantly, before thanking him for being on schedule. He then reveals that he ordered the previous SS assassinations to atone for the war crime they committed willingly. He then turns his back to 47 and tells him to complete the final contract.
A possible one. Just before the 10th Elusive Target was announced, an user on the official forums mentioned that he/she would have to leave town for work-related reasons September 16th. This would be his/her 10th ET, which meant that he/she would have just missed unlocking the Blood Money suit, forcing him/her to wait for several weeks for the next chance. After a brief discussion, a moderator promised to ask the team if there's anything they could do. The elusive target lasted for an entire week; Either because of this or it's a hell of a coincidence.
Every single kill in Legacy trailer references older Hitman games. The developers remember their players.
IO holding a fundraiser for cancer during the Christmas holidays.
Even after it was announced that Square Enix has dropped IOI, the developers are still active on the forums, and giving hints towards finding easter eggs. Even if IOI cannot keep making Hitman games, their final Hitman game is considered to be among the best games of the series and of 2016.
Thankfully this situation had a happy ending, as IOI retained the rights to the Hitman series, and would release a sequel two years later.
And another sequel has been slated for release four years later.
During the above situation, fans were kind and understanding towards IO, comforting them and sending them gifts, really showing their appreciation for the game's developers.
And we can't just forget how nice the devs have been to the fans from the start. Their forum moderators are active, and the team clearly takes player feedback into account. Had they just made another Absolution or ignored the fans, it's likely that the above would have ended the franchise.