John Byrne may get the glory of being the classic X-Men artist, but Jim Lee redefined the team in the 1990s and established himself as one of the premiere artists in all of comics. Here's five of my favorite covers from Lee's X-Men run. 
Next to the connecting covers for X-Men #1, Uncanny X-Men #268 stands as Lee's most memorable art for either series. First of all, we have Wolverine in his fan-favorite brown and yellow costume (which I wish everyday that Marvel would resurrect, but I'm positive that will never happen, at least not on a regular basis). It's also a perfect rendition of Captain America striking his most heroic of poses. By their sides is Black Widow, which gives this cover the trifecta. The cover alone makes this a key issue for X-fans.
The issue itself isn't anything remarkable, but this is a thing of beauty for Wolverine fans. Sans costume (and clothes, except for a loin cloth), Logan is brought to life in his most primal sense. He's all animal savagery on this cover, and that's what most fans of the character want in his depictions. Here is another case of Lee's attention to detail that helped define the comic art of the 1990s.
The visual of Havok destroying the X-Men logo is my all-time favorite cover featuring the character. Sure, it's neither the first nor the last time we see this type of visual with a character breaking apart the title on a respective cover. What makes this special is how the shattered title relates to the shattered team as the X-Tinction Agenda storyline led to a new direction for the X-Men.
Lee both scripted and drew this issue. While I'm not going to rank this as one of the greatest X-Men comics ever written, the cover pulls me in every time I see it. What makes Lee's art so captivating are the facial expressions, and he's captured Wolverine and Omega Red's masterfully. In today's world of comics where many artists snub the details, and the more rounded faces look like they came straight out of a Saturday morning cartoon, this cover recalls the old days of mature comic art.
Of all Lee's X-Men art, this is above and beyond the rest.
Magneto never looked so impressive. Of course, nothing says 1990s over-the-top comic art like a Holocaust survivor with a bodybuilder physique, but it's nonetheless magnificent. In this cover, Lee captured Magneto's fury with the artist's trademark white eyes. Never before has the Master of Magnetism looked so regal and so threatening. It's undeniably '90s, and it is nothing short of glorious.
On a side note, I could have placed all of Lee's connecting covers for X-Men #1 on my list, but I went with this variant in order to provide some variety. For that matter, all of his covers for those initial issues of X-Men, volume two, could be featured in his gallery as they are all comic masterpieces.
