Jean Grey

Main Comics (616)

 * 1)  Scott Summers / Cyclops  - Scott and Jean were strongly attracted to each other since they first met, when she joined the X-Men, but for a time, did not tell each other how they felt, each feeling the other would not feel the same way. Scott was also afraid that his uncontrollable optic blasts would be a danger to anyone he got so close with.

Jean was also the object of the affections of her teammate Warren Worthington III / Angel, although she never felt the same way.

When Jean began attending private college, she had a close relationship with her fellow student, Ted. Although he cleary wanted more with her, and the feeling may or may not have been mutual, it was not meant to be, as Jean and Scott finally confessed their feelings for each other and entered into a relationship.

Jean was placed in suspended animation by the Phoenix Force, and replaced by the Phoenix itself, imitating her, which carried on the relationship with Scott. This being eventually went insane and died. Scott moved on with his life, marrying her doppelganger Madelyne Pryor ad having a son, Nathan Summers, who had to be sent into the future to be cured of an illness. After Jean awoke and was discovered, it was realized that Madelyne Pryor was actually a clone of hers created by the villain Mr. Sinister and Madelyn, like the Phoenix before her, went insane and died. Scott and Jean later spent twelve years in the future raising Nathan before being returned to the present. Jean later found Scott to be having a psychic affair with fellow X-Man Emma Frost, who used the excuse that because their sexual encounters were only happening in both of their minds, it shouldn't count. This put a strain on the marriage, but shortly afterwards, Jean was killed in battle. Jean gave Scott a psychic push to allow him to move on from her death, and he soon after began a relationship with Emma.
 * 1)  Logan / Wolverine  - Although she was in a relationship with Scott, Jean and Logan also shared an intense mutual attraction from the first time he joined the X-Men. Logan was less shy about pursuing it, though Jean always rebuffed his advances in favor of Scott. The two shared kisses multiple times, however, when her resolve weakened.

Also, at least one issue in the 1960s showed that Professor X also had an unhealthy romantic infatuation with his student, but this appears to be brief.

Ultimate Comics

 * 1)  Scott Summers / Cyclops  - Some kind of romance must be the case in this universe.
 * 2)  Logan / Wolverine  - This love triangle simply must be a thing also.

Animated Series

 * 1)  Scott Summers / Cyclops  - As in the comics, Jean is in a relationship with Scott.
 * 2)  Logan / Wolverine  - Also as in the comics, she still shares an intense mutual attraction with Logan.

Films

 * 1)  Scott Summers / Cyclops  - Jean and Scott are already in a relationship when we meet them in the first film.
 * 2)  Logan / Wolverine  - As in the comics, she and Logan form a strong connection when he joins the X-Men. In the second film, this progresses to a kiss, but she still chooses to remain with Scott.

At the end of that film, she apparently sacfices herself to save the team. She turns out to have survived, but her powers have increased and made her take the insane form of her persona called the Phoenix. Her first act as the Phoenix is to murder Scott. Althoug she later kills Professor Xavier (who later turns out to have survived) and joins Magneto's evil mutants, Logan refuses to believe that the real Jean is still within her. After the climactic battle, with her powers going crazy and destroying everything in sight, she begs Logan to kill her, and he does so. This decision haunts him for some time to come.

Logan later participates in events that change the timeline from 1973 (ten years before Jean and Scott joined the X-Men) onward, before awakening in the alternate version of the present that he created, but has no memory of.

In the new timeline, in 1983, we see Jean and Scott first join the X-Men and meet each other, and the buddings of their romance. She also meets Logan for the first time, as she briefly manages to calm him down after witnessing his berserker rampage, only to have him flee into the woods.

When Logan awoke in the new version of the present, he finds both Jean and Scott alive, and in a relationship, noting "It's nice to see some things never change."