Here is an archive of all the past top five lists I've done over the years.
The friendship/flirtation between Wolverine and Jean Grey was so strong that it made its way into multiple X-Men films. Here, we'll look at the top five moments between the two. Note that I'm excluding the current "Jean Grey from the past" from the list, as she's pretty much her own character. I'm mostly excluding alternate universe stories, but I make a couple of notable exceptions.
New X-Men #117
For reader Inner Circle, I'll add this bit from this issue by Grant Morrison, Ethan Van Sciver and Prentiss Rollins...
X-Factor #37/Uncanny X-Men #242
So X-Factor and the X-Men run into each other for the first time since Jean Grey returned from the "dead" and the X-Men similarly returned from dying in Dallas during the Fall of the Mutants. Wolverine has to make sure Jean Grey is legit...
Not a terrible bit, but a bit too close to Adrien Brody/Halle Bery for my tastes.
What If...? #60
Kurt Busiek and Ron Randall did a one-shot when Cyclops and Jean Grey got married that went through different scenarios involving Jean and Cyclops, including one reality where she ended up with Wolverine. I just love this page. That look on Wolverine's face? Priceless!
Wolverine #75So Wolverine just had the adamantium pulled out of his body by Magneto. The X-Men are keeping him alive as they fly back to Earth, but their plane keeps getting hit by lightning during an electrical storm created by Magneto messing with the Earth earlier in the storyline (which led to the X-Men attacking him in the first place). Jean Grey, in particular, is using her powers to keep him alive. Meanwhile, Wolverine is ready to just give up and die, but Jean gets into trouble, and Wolverine goes away from the light for Jean...
Uncanny X-Men #394
The first issue of Joe Casey, Ian Churchill and Mark Morales' run begins with Wolverine, Jean Grey and Archangel running afoul of a bad guy who is trying to celebrate the anniversary of Magneto's attack on Cape Citadel from the very first issue of X-Men by attacking it himself. His reality-warping powers make it so that Wolverine and Jean Grey are pretty much done for, to the point where Jean is beginning to give up - Wolverine has to come up with a way to shock her back into fighting...
Uncanny X-Men #272/X-Factor #63
So Wolverine is without his healing powers and after fighting Archangel, he's in bad shape. Jean Grey comforts him.
Then, in X-Factor, when he is in even worse shape, she comforts him even more...
This is like a more tender, heartfelt and mutual version of the Inferno kiss.