Here are my favorites:
1) Exploring the Big Apple- the gold standard for NTR. Offers cheating, cuckold, threesome and vanilla paths. Very realistic story where the wife cheats simply due to arousal and desire. She has a loving husband who does satisfy her.
2) Girflfriend (by Erotic Drop)- multiple characters including engaged couple where the male protagonist has a cuckold fetish as well as a married couple where the wife is sexually unfulfilled.
3) Harmony Haven (by respirit)- A new game which is still in its early stages. I have it listed high on my list due to its potential. Good looking loving couple whose fidelity will be tested.
4) Watching my Wife- Abandoned game, but a great story. Married couple where the husband's actions dictate how far the wife will go in cheating. Offers cheating, cuckold and swingers paths, but the cheating path is done the best. Wish the developer didn't abandon it as there was so much potential here.
5) Pineapple Express- Fun story from the same developer as Exploring the Big Apple. The couple is not married or engaged, just living together for a while. There is a cheat path, cuckold path and a vanilla path. The cuckold path is cliched already with the usual BBC and femdom tropes. The cheat path is interesting and is brought on by her seeing him return an innocent kiss.
6) Not So Shy- Again, this is high on my list for potential more than anything else. The wife saved an SD card showing a video of her having sex outdoors with her ex bf. The scene is straight from a porno movie.
7) Thot on Trial 2- Good looking young married couple. Husband is an asshole sometimes and the wife enjoys smoking weed behind his back while she flirts with her neighbor and ex bf. Very slow moving story and still in the potential zone.
8) Because I Love Her (first version)- Engaged couple, he has a cuckold fetish, she craves BBC, yada yada yada. I only like it because she's good looking and there are two cheating scenes.
9) A Wife's Life- Too bad it is a text based game. Long story but it gets tedious navigating between the phone and the text messages. Great porn clips, cheating wife story. Left off where the husband must decide whether to accept being a cuck or leaving her.
10) Onlyher- The prologue is riveting and interesting. Man marries his ex-boss who will then do anything to protect him, including sleeping with his new boss (yandere mode and/or cuckold mode available). My only knock on this game is that the developer decided to switch to sandbox mode for the main story.
Honorable mentions:
Next Steps
New Neighborhood
Memories
Naughty Wife Natasha
My Wife's a Star
A Life Worth Living
Exciting Games
Undercover (zany comedy)
Wifey's Dilemma
Day by Day
The Adorable Marriage
College Love Triangles
Boundless Lust
My Husband Doesn't Know (abandoned too soon)
A Wife's Loyalty
Navigating the Rift
Innocent Au Pair
Babysitters
The Adventurous Couple
A Couple's Duet of Lust and Love