Part of what makes Geralt of Rivia a popular character is that he is not your run-of-the-mill noble hero who saves the day. Instead, he is a complex man who does both good and bad things with his abilities. A lot of this is left to the players' choices throughout the games. No matter what though, it is clear that Geralt is a man who prefers the intricate middle road over the cliches of good and evil.
Due to these characteristics, Geralt has done both shady and noble acts throughout the books, games, and T.V. show. When it comes to the games, the specifics are usually left to the player. For most players, their Geralt has typically done a mixture of shady and noble acts. Even players who value the good choices in every game is often forced to make a shady choice once in a while.
10 (Shady) Bound Himself And Yennefer Through A Genie Wish
This was a part of Geralt that was out of the hands of the video game players. For those that read the book or watched the show, Geralt bound Yennefer and himself together through a Genie wish. It could have been much worse, like forcing her to love him. However, it is the beginning of why their relationship is so tumultuous from then on. They definitely are not the most romantic video game couple out there.
The wish was made without Yennefers' consent. For most women, this scenario sounds like a shady nightmare. Luckily, there is a quest in the third game that can undo the wish.
9 (Noble) Saving People For Free
Geralt is a gig man. He roams the land looking for work. Sometimes such works includes saving lives. There are also times Geralt decides to do such work for free. This can be due to the people's inability to pay due to poverty, or just a personal ethical choice by the player.
A man has got to eat, but it can also just feel good to save lives for the sake of being a good person.
8 (Shady) Accepting Coin To Give Ciri Back To Emhyr
Ciri's father, Emhyr, makes Geralt an very shady offer in the third game. He wants Geralt to bring Ciri back to him, so he offers Geralt coin. At this point, Emhyr doesn't really know Ciri and Ciri is like a daughter to Geralt and Yennefer.
Luckily, this is a players' choice. Most refuse to basically sell Ciri for money. To do so would be a betrayal to her and everyone else who has grown to care about her.
7 (Noble) Helped Smuggle Mages To Safety
Geralt doesn't really get a reward for helping Triss smuggle mages to safety (unless you count romancing Triss as a reward). The mages are being smuggled to safety because they are all being burned publicly at the stake. It is pretty disturbing, as you can constantly pass their charred corpses throughout the city.
Helping Triss get these mages to safety is a noble act because mages have not always been nice to Geralt.
6 (Shady) The Crookback Bog Choice
No matter what choice players make in this questline, lives are lost. It is basically just choosing whether to sacrifice children to some horrifying bog witches or letting an ominous spirit wipe out a village.
It is a pick your poison sort of choice, and it is a requirement for the main questline so it cannot be avoided by those who wish to beat the game.
5 (Noble) Sparing Certain Monsters
Not all monsters are bad. In fact, most of them are like animals that just act on instinct. With that in mind, it can be nice to not have to kill them. It could take some extra work, but Geralt can reach a compromise with monsters.
It doesn't happen often, but players do get chances where they can spare monsters. There are those that are intelligent enough to cut deals, like godlings and succubi.
4 (Shady) Betray Roche
Roche is a longtime friend of Geralt, but in the third game the player has the choice to side against him and get him killed. It is quite shady because you've been with each other through so much.
The one reason a player may betray Roche is due to their political standing. However, it does seem unlike Geralt to betray a friend over politics which makes this option even more shady.
3 (Noble) Being A Good Father To Ciri
Geralt has gone through a lot, and that can make it easy to become selfish. With Ciri though, players have a lot of room to be good to her. Being good to her means letting her grow, make her own decisions, and be who she wants to be. How players treat her is one of the big influences of the games' multiple endings. Being an over-protective and cynical father figure to her can get her killed while being encouraging and open-minded can get her to survive and thrive.
What makes this noble is that to be a good father is to be selfless. Being over-protective is to protect Geralts' feelings for Ciri, not Ciri herself.
2 (Shady) Kill Keira Metz
Keira, like many other sorceresses in these games, is fond of luxury. In the third game, she has been forced into hiding and has to live in the swamps of Velen. Through her questline, Geralt can find out that she is plotting to make a deal with Radovid by giving in important notes on plague research.
Upon learning this, players have the option to kill Keira. This is shady because she is a bit of a long time friend not only to Geralt, but to other sorceresses like Triss and Yennefer.
1 (Noble) Promote Harmony With Nature
Despite this lesson being everywhere in the games, players often forget about Geralts' feelings on nature. He often gives villagers and towns a lot of criticism if he can find out it is their fault monsters and spirits were provoked in the first place.
Geralt is incredibly knowledgeable about monsters, so he also knows when it is humans who are to blame for disrupting the natural order of things. He will do the job, but he won't do it without making sure the humans know that they messed up and are the reason this is happening first.