Who would you say has gotten noticeably better with age, and who has stayed about the same or even degenerated?

Way, noticeably better:
Tim Truman
Mike Deodato, Jr.
George Perez
John Romita, Jr.
Steve Leiber
Chris Cross

About the same:
Rob Liefeld
Mark Bagley
Ron Frenz
Ron Lim
Jim Starlin
Paul Ryan

Worse
John Paul Leon
Frank Miller

Gil Kane never stopped improving. (I wish the stories he was hired to draw kept improving too, but you can't have everything. )

Dan Jurgens' growth as an artist looks impressive to me.

Art Adams comes to mind. His stuff gets better and better.
All 3 Kuberts get better and better.

Which is Andy and which is Adam? I always get them mixed up.

What does JPL do these days? I loved his work on Earth X (although it did take an issue or two for me to warm to it - I got so hooked, though, that when Universe X came out, the 'traditional' art just looked wrong!) and a couple of other gigs he's done.

Artists who got better:

Cary Nord (compare his DD run with Kesel to his Conan stuff)
Mark Bagley (his Ultimate Spider-Man run is much better than his Amazing run)
Paul Smith (always outstanding, but always improving)
Brandon Peterson (the leap from Ultimate X-Men to Ultimate Extinction is impressive)
Stuart Immomen

Andy did adjective-less X-Men, 1602, Origin, and is currently on Batman.
Adam did Wolverine, Hulk, Ultimate X-Men, Ultimate Fantastic Four, and is currently on Action Comics.

There were several artists in the mid-90s who got worse, but it was because of editorial interference. "You need to draw like Rob Liefeld". Worst period of comic art ever. I remember Teen Titans (or was it New Titans by then?) going from classic superhero art to scrawl, to name just one.

Artists whose styles just changed for the better, or they learned more about anatomy, whatever:
Deodato
Perez
Bagley
Joe Shuster
Joe Kubert

I'm not good at naming names for people who get worse, and it's so subjective. I don't care for later Gil Kane or the more recent Neal Adams stuff, but it's hardly "worse".

A lot of artists get more technically proficient but stop being as inventive and energetic. They discover neat standard poses and shots that always do the job and stop looking for the fresh interesting approach. In another thread some suggested it was because they were no longer trying to prove themselves, which makes sense to me. And many artists will tell you that some of their best work comes as a result of accident or even mistake, something expertise actually works against. So I guess it's possible to get both better and worse, if you see what I mean.

All artists really hit a peak and then go down from there.. In RARE occasions there are artists who never seem to fade but even the greats... Kirby, Adams, etc...work didnt maintain....

Art Adams, Adam Hughes... those two seem to just get better...

Yeah, Neal Adams' recent work bugs me. It's really -- ugh.

I can't quibble with a single suggestion thus far. I'm pretty sure I agree with it all.

The Kubert brothers went from two artists I just didn't like in any way, shape or form to two solid artists whose work has come a long way. I like what I see from them these days and really appreciate their artistic development.

Frank Miller was once a favorite, but he hasn't drawn anything I've liked since 300. He's at the point of self-parody these days.

John Byrne splits this. His storytelling very much improved over the years, BIG jumps over what came before, but I find his linework has grown less exciting and dynamic; kind of by the book.

John Romita Jr. is LIGHT YEARS ahead of where he used to be ... and I was a fan of his work from the very start. His work never stops evolving. I like that.

Bagley is about the same as ever. His work varies WILDLY depending on his inker, but by and large he's a rock solid artist and a very good storyteller.

Finally, JACK KIRBY. There was a guy who never stopped developing his craft. He may have tailed off in his last few years, but he was constantly pushing forward. I feel like he never stopped getting better. Even though his stories declined, his art didn't.

John Paul Leon's (and Bill Reinhold's) art on Earth X was outstanding, imho. I thought this was one of the best drawn (and written) mini-series to see print in recent years.

One artist whose work hasn't lost anything is Gene Colan. At 80 years old, the Dean is still producing terrific work. I'm very much looking forward to the Ed Brubaker-written Captain America story coming out later this year.

Also worthy of note, are the paintings Carl Barks produced in the years shortly before his passing. Incredible work from a man in his 90's.

Byrne: used to be the best by far. Now is just a good artist. Alf as good as he used to be. maybe not even that, yet he is still better than most of the artists out there. The problem is that there is too lot of great artists, who are almost as good as Byrne used to be, and far better than he is today.

Romita JR always improving until the Cable mini serie with Nicieza, were his work was, even if very good, exactly the same as on his previous books. from there on his art as been decent, not improving, declining a little bit, but not too much. Untill 2000 when Queseda became EIC and JRjr was paired with JMS on amazing: Then he began to improve again. slightly, but really.

Liefeld: An artist full of promises when on New Mutants, still good on X-Force. Then came Image comics and Youngblood. From this point on, his work became worse and worse.

Kirby: He always improved his art, but the great jump in quality was during the mid 60s. And it may be depending more on a general change in the way to do comics, with more time, and more finished art, than something that would be specific to Kirby.

Carlos Pacheco's art seems to get better every time I see it.

One name that sticks out for me: Herb Trimpe. I felt he was a good solid artist until his work on Guardians of the Galaxy. Blech. He looked like a 3rd rate Liefeld.

I could be wrong, but I think Trimpe later wrote that he was essentially told to draw that way if he wanted to get work. If so, it's a shame.

Thats what i heard too.

I like Miller's recent work.

Guess I'm just crazy.

I wonder could Miller flip a stylistic switch in his artistic brain, so to speak, and draw like he did back on Daredevil; or flip another switch and draw like he did on Elektra Lives Again; or the same again with the original Sin City? I mean, are all of these styles still available to him, or has he moved on irrevocably?

I'd guess he can flip a switch. Back when 300 came out that was quite different than Sin City, and neither one looked like Dark Knight Strikes Again.

I agree there are noticeable differences in style between Sin City, 300 and DK2, Matt, and that that shows that he can alter style somewhat depending on the subject; however, I think there are strong family resemblances between those three styles by contrast to the stylistic jump between, say, Elektra Lives Again and Daredevil. Could he now return to the slick style of DD or the grotesque, jagged one of Elektra Lives Again? When he provided the new covers for the Daredevil: Visionaries collections a few years back, he drew the figures in his contemporary Sin City: Hell and Back style; could he have done otherwise?