Bob Hall wasn't so bad. As one of the few graduates of John Buscema's short-lived comic art classes, he had a firm grasp of Marvel-style sequential storytelling. The problem with that Avengers run was attributable to his following Shooter's constipated layouts (much as Dave Wenzel was hamstrung by them for the conclusion of the Korvac storyline earlier). I quite liked his issues of Super-Villain Team-Up, especially because he is the only penciller to model his Dr. Doom after the Gene Colan version rather than Kirby's. Hall was certainly better than Don Perlin, whose stiff, ugly art drove first Werewolf By Night then The Defenders straight into their graves.

Cei-U!
The defense rests!

One man's terrible is another man's awesome.

Love me some Ditko; it looks dated, but I still love Ditko's stuff, much the same way I feel about Kirby as well.

Can I be the boring one and say I don't feel I can buy/continue buying a book when the art isn't appealing - no matter if the story is good.

I can do the reverse: Frank Miller's All-Star Batman did not appeal to me. I gave it about five issues - when DC could be bothered to put out this so-called bi-monthly title - but gave up. Jim Lee's art is beautiful. I didn't like the story.

Actually, to be fair to the premise of your question, I am a Judge Dredd fan. There will have been Dredd artists I don't find appealing, but the character and his world is compelling, so I do stick with it. 

Well, even the most generic late '70s-early '80s is preferable for me over the overly-cross-hatched giant thighs and wee heads look of a bit later. I do understand about Bob Hall, Don Perlin or even Steve Ditko (at times) being disappointing. I love Ditko Hulk myself (and Machine Man) so would want those issues specifically because of the art, but not so much on some of the other comics of that time (Daredevil, Micronauts, Captain Universe).

The New Defenders was something I kept buying for the writing but not the art (except for the often incredible covers by various artists), although Kim DeMulder as inker helped... also Sal Buscema Rom and Hulk, and She-Hulk and Dazzler for a long time which were solid but bare bones. Remember those Michael Golden Rom and She-Hulk covers? Bill Sienkiwicz Dazzler covers? It helped to pair above average cover art with average interiors in my opinion... also got me through those Chaykin layout issues of Micronauts before Pat Broderick. Spider-Woman by Jim Mooney kept me just long enough to still be there for the great run by Claremont with Leialoha pencilling (and sometimes inking as well).

My pick would be the Herb Trimpe issues of War Of the Worlds in the early '70s written by Don McGregor. The art wasn't the reason I have them at all, though I have seen some Trimpe art from earlier and later that I did like a lot.

If its okay to do this, I will add a "bad art" run: The Invaders (1975-1979); BIG fan of the love and creative highs Roy Thomas achieved with his retconned Golden Age stories in general, but the artwork of Frank Robbins (issues #1 - #28) left much to be desired (I went into that at length in another thread). The Invaders was the textbook example of an interesting, important series (in the continued building of the Marvel Universe's past) with occasionally great covers, but those covers turned out to hook readers into buying something with interiors that never held up their end of the artistic obligation.

I liked the Bob Hall stuff in Avengers as well as the couple of issues of his work in Thor that I've seen.

Loved Frank Robbins art and felt it fitted the time period more than anyone else who worked on the series. It was at its best with Frank Springer inking, though. Robbins' stuff looked like the Golden Age, it felt like the 1940s. His rubbery figures and cartoony style made the action flow and added a visual excitement, in my opinion.

You want to throw out bad art: Chuck Beckum/Austen, on Miracleman. Man that was a horrid mess, picking up where Alan Davis had left off. Thankfully, Eclipse agreed and he only did the one issue and an ad. What I saw of Austen's later art wasn't much of an improvement.

For really bad art, look at Now Comics' Speed Racer book. When the movie came out, whoever had the rights republished it in trades and I had seen better amateur art in fanzines. It was terrible. It made some of the Malibu stuff look like Tower.