Astro City!
Awesome! Since manga is allowed, my next choice would be Yu-Gi-Oh! from Kazuki Takahashi (R.I.P.)
I'd agree. It's a bit weird that the artist left and a new guy took over for 187 issues. It's a bit odd for both of them in that Tony Moore hasn't done anything else on that level so he's defined by drawing less than five percent of a notable run, while Charlie Adlard did so much work, at a very high level, but could not surpass the impact of that first volume.
Sincerely,
Thomas Mets
For me and I will repeat a couple of what has been said.
Stan Lee/Ditko Amazing Spiderman.
The Walking Dead.
But I have a couple of my own.
The Fantastic Four. The first few issues you have the Origin, An Alien Invasion with the Skrulls, Doctor Doom and Namor. It introduces a lot and it is a mix of what the Fantastic Four will be with Cosmic and Super Villain adventures.
Also Garth Ennis Punisher - (I am not the biggest fan of The Punisher but I love the Max series) And the first arc really set the tone for how dark, gritty and realistic (To a point) that this series would be.
This Post Contains No Artificial Intelligence. It Contains No Human Intelligence Either.
Definitely, my next choice would be Fushigi Yûgi from Yuu Watase
Agreed on Savage Dragon- Erik took it in some questionable directions at times after this, but the set up in the first 6 issues is superb. So much world building, and just throws the reader into this living/breathing world of powered heroes/villains. I'd be happy to include Ditko's first six issues on Spidey and Dr Strange, Moore's first 6 issues of Miracleman and Supreme, and most things that Brian Vaughan has written. Maybe as well DeConnick's Captain Marvel.
Definitely, my next choice would be Steam Detectives from Kia Asamiya
I love the way Byrne's Alpha Flight starts out with the first 6 issues. We get 4 main stories (Tundra in #1, the Marrina / Master story in 2-4, Puck in 5 and Snowblind in 6.)& origins of Guardian and Shaman in the backup features.