Most of them I think i kind of carried forward, in general, though I discovered some others, in retrospect.  Captain America and the X-Men were early marvel favorites and that carried on for quite a while, though far longer with Cap then X-Men (which tapped out in 1982, apart from reprints).  At DC, it was Superman, Batman and the JLA and those continued on for decades.

However, I always had a healthy interest in non-superhero stories; so that interest always stood me well.  Jonah Hex and Bat Lash hold up well, as westerns and have inspired some really good modern takes.  Sgt Rock and Enemy Ace still invoke thoughtful ruminations on the nature of war and those who fight it.

Humor was always a big part of my reading and I still have a great fondness for Uncle Scrooge, the Junior Woodchucks, Super Goof, The Three Mouseketeers, Richie Rich, Archie & Jughead and those that captured the same light spirit.  However, I have lightened up more about some superhero comics and am more open to the goofy then I was in my teen years.  I had my period of railing that the Adam West Batman held back the true Batman, until he got so damn grimdark that I realized that a good portion of that show (the first season and about half  to 2/3 of the second, and the movie) was pretty damn entertaining and had more fun plots.  Adam West was a heck of a lot funnier than Joel Schumacher and a better detective than either Michael Keaton or Val Kilmer (don't get me started on George Clooney.....that was worse than 3rd season Batman).

Favorite characters today would be ones like Bone and Jack Knight, who came into existence later or books like American Century or Iron Empires, which wouldn't be done back then (Iron Empires might have, in a more dumbed down fashion).  I also gained an appreciation for more than just American companies, though, back then (late 70s) I was just learning about them; and, later (1990s and 2000s) I was reading them.

Growing up it was Batman, Spider-Man and The Thing, in that order. Followed by most any Earth-2 character.

Now…I don’t have favorite characters. A character is only as good as the creator working on the story. Bad creators are going to make any character stink. Good creators can make “bad characters” great.

Except Superman. He always stinks.

Across early childhood and into adolescence? Short list: Batman, Phantom Stranger, Green Lantern, Robin, Spider-Man, Doctor Spektor, The Punisher (70s version), Enemy Ace, Captain America, Falcon, Secret Agent X-9, each member of the Fantastic Four, Alfred E. Neuman, Superboy, The Spectre, various Archie characters, a ton of horror "hosts"/mascots (e.g., Uncle Creepy, Cousin Eerie, Cain, Abel, Mordred, Mildred and Cynthia), Doctor Solar, et al. I still appreciate the characters from the period in question, so there was no desire to "replace" them with other characters.

My first favorite comic book character was Spider-man, and then many others followed. Now, though, I don't think I really have a favorite character.

Especially Silver Age Superman.

Fun question!

Spider-Man was my first and still favorite after all these years. The closest of seconds however is the Legion of Super-Heroes, another early discovery as a kid, and likewise still a major favorite. Rounding out my top 3 is the FF, early childhood again, and while slightly behind the other 2, forms the trio that still towers over everything else for me.

There was a period in the early 80's where "Wolverine-mania" was going on and I got swept up in that for awhile. I would have said Wolverine was my #1 back then in fact. But eventually the character got pretty overexposed and for whatever reason, has not stood the test of time for me though I'm still an X-Men fan and like him generally.

Also from the 80's, for some reason the Badger just hit that right spot for me, favorite indy of all time. There were only so many years of material I liked and later treatments never did much for me, but I still have great sentiment for the character and absolutely consider him a favorite for life.

My last "favorite" is probably Deadpool, he was a fun addition in the 90's kind of bringing some of that wise-cracking Spidey style fun (in a twisted crazy way though of course!) and while he definitely got overexposed over time similar to Wolverine, for some reason I still have a good affinity for him. I love the oddballs, what can I say.

A few other honorable mentions would be JSA/Earth-2 characters (All-Star Squadron pre-Crisis hooked me, mostly Elseworlds stuff for later treatments), the Shazam Family, and the Superman Family (particularly Superman, Supergirl, Jimmy Olsen, and of course my man Streaky).

I find it great to see how our different age leads to our having wildly different favourites!