Which charatcer\campaing did you most involved yourself?

[Quertus]

The character that sticks out in my memory the most was Cenrien Greenwood, an elven battlemage. At one point he became a death knight somehow and spread the death knight curse to another person. Eventually, the two death knights dueled to the death and he barely won it, and as a result became owner of an entire castle. The castle was later overrun by a huge undead army though.
Mr. Greenwood was the only character I played who actually managed to father children. He had 3 of them, I think.
It was years ago, and he did lots of awesome crazy stuff, but my memory of it all is a bit fuzzy. He eventually died from getting blasted by a hag's fireball.

That Viking character seems pretty interesting. It almost sounds like his story could be made into a tv show or something, though it does kind of remind me of Eragon. A female elf, a dragon, a teenager who becomes a dragon rider living on a farm near a village, etc.

Was that Armus guy a cleric, then? And I am curious why you chose to reduce his strength.

No, Armus was not a Cleric - I thought that "lay follower" conveyed that. The GM at the time probed me for details about the hierarchy of the church (which had been much more than decimated when the world quite literally blew up**), and was surprised to learn that Bendeth's was one of the few religions where the position of High Priest did not require one to actually be a Cleric.

If I made an Armus-like character in 3e, I'd probably make him a Commoner, then ask the GM for a custom prestige class to make Commoner weaker. In short, Armus is all about player skills (although items help, at times a lot!).

Player skills, and tactics. In his "normal" party, Armus would generally move to protect someone with better defenses than himself, for reasons even the Playground has yet to divine.

How did a Death Knight die to a Hag's fireball? Was he already on (un)Death's door?

** In retrospect, I'm not certain whether the world blew up due to the actions of the party (we were messing with powers beyond our comprehension (not that that says much, given our comprehension)), the actions of the beings that we didn't murder to death (friend or foe), or the actions of semi-parallel campaigns in the same world. If that last one, then the destruction of the world may have been my fault...

Armus also look like a really interesting and complex character, it would be interesting to DM a session with you playing with it, to see how it plays out.

I've been struggling to find a way to word this that doesn't sound like metagaming, but... Armus relies a bit on Knowlege:GM. Single sessions with Armus aren't usually as interesting as the long-term plans and manipulations he engineers. Which are only successful (or, at least, fun) if I know what kind of plans will be fun to engineer under a given GM.

For a normal one-shot... hmmm... one party asked him about his gear. Armus explained that "this sword was a gift from a now-deceased dwarven king; this sword was a gift from an angel after I freed it from captivity; these boots were made from the skin of a snake that disturbed me before an important diplomatic meeting to unite not-yet-warring city-states", etc*. Then I was told that one of the party members had a Ring of Truth, and was asked how that sounded to him. OOC, they learned a lot, as I struggled to parse Armus' tale - unlike most of my characters, Armus views "the truth" as just another tool, and some of his descriptions involved bending the truth a bit, viewing things from a certain PoV. But, as it was all technically true, their characters learned less than the players themselves did. Otherwise, Armus' performance in the session was... lackluster. He makes tactically correct decisions without the moxie to back them up. And, if necessary, utilizes items to bridge the gap.

Another one-shot, Armus makes a deal with a Wizard, then meets an obvious PC.

Armus: "Um, I'm quite happy with this deal, you really don't need to convince me with a Geisha Girl or anything..."
PC: "Geisha Girl? Do you think all Geisha Girls wear platemail?"
Armus: "... only the good ones."

Did I mention Armus' significant Wisdom penalty? Yeah, definitely not a cleric.

As part of the series of adventures, the party met Important NPC™, who was also Beautiful Woman Important NPC™. She invited the party to join her for dinner, and sat at the head of a large table. The players all wanted to get on her good side. The players could see the gleam in my eyes as they vied for position around her. But Armus just waited. Some of the other players grew nervous at the gleam in my eyes as I said not a word, and Armus just waited. Once everyone had sat down, Armus strode to the opposite end of the table, sat at the opposing head of the table, and declared, "I'm glad everyone knows their place". That's the kind of little stunt I enjoy pulling with Armus.

* "this bow was a gift from a Bladesinger mentor; these arrows (and pants and tunic) I made myself; this cloak, I found in the ruins of a dead city; this rope, I was bound with by Drow, and used to strangle one of their High Priestesses; this walking stick, I looted off my own dead body". Or something like that.

I think Armus would make a good supporting character, but I think also he could make a decent leading character as well.

Armus did both. He started the series of adventures as the party's kick-me, and ended it as party diplomat, party leader, and high priest. I'm struggling to remember any other characters I've played that acted as party leader, come to think of it.