There are some, of course, who are still "old school" -- Bruce Timm, Adam Hughes and JRjr excell at this -- but I can't think of many others (this side of the Pond, anyway.)

But increasingly in the past couple of decades, artists have turned more and more away from this kind of thing -- everybody stands the same way, walks the same way, jumps the same way. It's as if there are "rubber stamp" poses, to which the artists merely add costume lines.

I've thought the same thing. It seems action scenes have suffered most. They used to have a sequence of events within them that the reader can understand. "First Cap throws his shield, then the Hulk grabs it and throws it back, then Cap leaps over it, ..." Now it seems like they're comprised of random action poses with no actual content. "Superman is punching Amazo in midair, now Amazo is doing it, now they are both doing it..."

Stuart Immonen is good at giving different stances, Humberto Ramos, Bryan O'Malley, too.

I think most people like that are working in videogames or animation right now. I'm often amazed when rereading older comics since many fight sequences remind me of games I played like Devil May Cry and so on. When you get multiple characters to chose from, they usually have different walk animations and attitudes as well.

I also think it's a matter of "fashion". It's not really fashionable to do this in comics right now or I just don't notice it because the writing is usually bad and I don't pay attention. I'm sure if I thought more about it, I could find alot of names.