Factoring all runs over the years...

It gets tricky on some of these runs since a few (like Spider-Man, FF, X-Men) had companion titles,
which are hard to exclude, and which may have increased exposure and/or diluted some of the appeal over the years.

That said, I'll try to restrict my comments to the main titles:
Amazing Spider-Man: loved Ditko, loved Romita Sr., and enjoyed the title when I was a kid in the 1970s. Lost interest afterwards.

Fantastic Four: really powerful Lee/Kirby run then after the first couple of years, the first half of Byrne's run, Walt's run appealed to me.

Uncanny X-Men: I enjoyed the young team from the 1960s, and was really onboard the relaunch in the mid 1970s. Lost interest
about the time that Wolverine started to show up in everything.

The Mighty Thor: again, the later Lee/Kirby run is excellent, and a wonderful epic run by Walt.

Captain America: I have almost never read this title and almost never bought more than a spot issue now and again.

The Invincible Iron Man: really dug the early Anti-Commie 1960s run, and have enjoyed the title off and on afterwards for
different reasons (quality writing and artwork, but not always at the same time).

Daredevil, The Man Without Fear: I have loved this title through thick and (often) thin. I have cooled on Miller and Bendis runs
after the fact, but, both were very good.

The Incredible Hulk: I was never much of a Hulk fan, but I acknowledge there have been some excellent moments.

Dr. Strange: I have almost always enjoyed Dr. Strange from the early Ditko serialization stories and afterwards.

I'm going to vote for Daredevil. There's a good variety and something for most everyone to like in it throughout it's run. And while
I very much enjoyed many of the other titles, DD is a title where I can randomly pick up an issue from any era and enjoy it for what
it is/was. Every other title on the list I would have to cherry pick my era to really enjoy it.

FF if only for the Lee/Kirby run but it was good in the 70s out John Buscema, Rich Buckler and Keith Pollard. Byrne's run was.good and Defalco and Ryan's run is underrated. I haven't read that much of Waid/Weringo or Hickman but they are well regarded.

I did enjoy the early goings of the Hickman run on FF, but it also tied into the Future Foundation title (or whatever
that was really called). I did hear nice things about the Waid/Weringo run after the fact, but I missed out on it.
I enjoyed Waid on Daredevil, so I suspect his FF would be good, and Weringo's art was quite nice.

Also Walt Simonson's run.

My friend Daphne.

Right!

It's down to FF and Spidey for me.

The FF had multiple enjoyable runs, Simonson being my favourite and DeFalco/Ryan being my son's when he was little.

But Steve Ditko alone puts Spider-Man at or near the top, If the Superior version is allowed to be included, then I'll say Spider-Man.

Daredevil, and it's not even close.

It didn't have the equivalent of Lee/Kirby on FF or Lee/Ditko on ASM, but since Frank Miller, it's almost always been, at the very least, a consistently enjoyable book, and far more often than not it's been terrific. Just this century alone, the Bendis/Maleev run, the Brubaker/Lark run, the Mark Waid stuff, Charles Soule, and now Chip Zdarsky have all been wonderful stuff.

Waid/Samnee is a very excellent run. That's about when I stopped buying comics. David Mack did okay, too,
and Ann Nocenti doesn't get enough credit. And, although the writing is suspect in much of the 1960s, Gene
Colan always did excellent work on the artwork. D.G. Chichester's Fall From Grace is pretty good, too.

Never cared much for the Kevin Smith period, but Joe Q's artwork was interesting in and about that time.
I'm also not a big fan of Romita Jr in general, but his style worked okay for the DD title, I thought.

I’ve always liked DD but it’s funny before Miller it was a C-list book and was bi-monthly.

It wasn't always bi-monthly, and as for C-List, I don't know. Some of the stretches with Thomas, Wolfman, Shooter, Conway,
Gerber were C-level writing, but they almost always had some quality art coming from Colan, Brown, even Don Heck during
the Black Widow/DD team-up issue phase of the early 1970s. And along the way there was almost always something of
interest going on: Wally Wood in the single digit and teen issues, Lee and Colan with Jester in the mid 40s, Thomas with
Barry Smith inked by Johnny Craig in the early 50s. A few interesting villains: Death Stalker, Bullseye show up to keep things
interesting before Miller shows up. Certainly a much better title after Miller, but often in the B range beforehand.

Thor for me.

I don't disagree with you and I liked Bob Brown's run, too. But I think it was felt that DD didn't separate from being like Spider-Man until Roger McKenzie and Frank Miller. Though, it can be argued that Jim Shooter, Gil Kane and Klaus Janson started DD off on that darker style.

Kirby's FF and Thor were great.
Ditto Ditko's Dr. Strange and Spider-man.
Starlin's Captain Marvel and Warlock epic was fun.
Miller's Daredevil, Colan's Daredevil, Colan and Englehart's Dr. Strange.
But for sheer variety of styles and stories that I enjoy revisiting, it's Steve Gerber's Man-Thing run for me.

I've wondered if Wally Wood had been treated better and had gotten the credit he deserved,
if Daredevil might have become more of an espionage / counter-espionage comic, more along
the lines of The THUNDER Agents and also along with what was happening in Strange Tales with
Nick Fury's make-over. With the popularity of movies like James Bond and TV shows such as
The Man From U.N.C.L.E., I could see those two titles merging. The later What If? with DD and
SHIELD shows one possible result, but imagine adding a lawyer element to SHIELD.

I think DD might have become more of a world traveler, possible diplomat/detective.

Amazing.

Fantastic Four by a nose over Amazing Spider-Man.

This is my vote as well.

The Claremont/Larroca run is also awesome, of course.

FF for me. Lee/ Kirby, Byrne, Simonson and DeFalco and Ryan.

It's Uncanny X-Men for me.