Re: Red or Lance
Personally, I'd have to go with Red. Let's break this down in a detailed way.
First up, is in a gameplay standpoint. Higher-leveled mons, in an area occupied by strong mons as well so that it's treacherous to get TO him, and a requirement of twice the badges to face him, Red was, as everyone knows, built as the ultimate last challenge in GSC and HGSS. Lance became the Champion, so he's no slouch either. Also from a gameplay standpoint would be how the fights actually pan out. And here's where the common Type Diversity argument comes up. Lance specializes in Dragon-Types, just like he did as the top of the Elite 4 three years prior to the events in GSC/HGSS. However, he still has a good diversity while keeping to this theme...if you accept the fact that half his Team is the same Pokémon, that is. Yes, that is one thing that is his downfall, but he includes Charizard, Aerodactyl, and Gyarados into the lineup. And the latter of those three is relatively easy in Gen 2, but with the upgrade to the battle mechanics in Gen 4, it actually becomes a threat. Your Pokémon better be a good Electric-Type to deal with it quickly before it gets you, because the Phys/Spec separation makes him dangerous. Ice-Types still rule the fight, pretty much, but two of his Pokémon don't take SE damage from those attacks, and one (Charizard) is even threatening to them.
In the meantime, Red has a completely diverse Team consisting of the original starters' final evolutions, that damned Pikachu, Snorlax, and, depending on which Generation game you're playing, Espeon (Gen 2) or Lapras (Gen 4). The Pikachu leads, and is his highest-level Pokémon, making it a threat regardless. The rest of the match is a slugfest (especially against that @$%*#! Snorlax)That will test your knowledge, skill, and time spent griiiindiiiing your mons to be able to take him. He is THE toughest match in nthe entire series, even his Gen 2 fight was tough. Given the choice, I'd rather fight BW2 CYNTHIA than him, if we were talking about ease. Red also holds a unique nostalgia of being the Player Character of RBY/FRLG, so in essence, it's like you're fighting YOURSELF for the title of Greatest Trainer in History. That's a unique, ridiculous kind of feeling that hasn't been duplicated (considering GSC and HGSS are essentially the same thing, my point still stands).
That's gameplay. Let's talk about lore.
Lance was what we thought would be the greatest challenge of the Elite 4 the first time we ever played RBY (until we realized stupidhead went first), and he terrified many new trainers. Those Dragon-Types were fierce and hard to control, and he did so with plenty of expertise to school trainers who think they're all that. He is commonly the last one the luckiest and most skilled trainers reach before their downfall (not including the Player Character and...you know), so his title as Dragon Master isn't something to laugh at. It's jumped up when the Elite Four is revamped after Blue and Red trounce them, leaving Lance to wander around and do his own thing for two years before becoming the new Champion for aspiring trainers to be shot down by. He's stronger and more diverse with his Team; sure, only a single addition, but that kept to the Dragon theme (Also note that in this aspect, it's not the levels that determine everything, because Lance's Pokémon went DOWN in levels between RBY and GSC to counter how much harder it is to gain exp and levels in the latter). Once more, Lance was on top where he more than likely felt most comfortable. A final test to determine who is the greatest trainer of the era.
And yet, there truly is one more test. I go back to what I said earlier about Red being the PC from a previous game for you to encounter and overcome. But let's get deeper into Red himself. He has hidden himself in one of the most remote areas in all of Kanto or Johto (indeed, despite the mountain officially being a part of Johto, it's right smack dab between the two regions) to train, meditate, and await any who might find him for yet another trial of strength, dedication, and virtue. It's assumed that Red specifically asked Prof. Oak and the League to restrict access to Mt. Silver to anyone who doesn't have all 16 badges to ensure any remaining battles he has would be against a similar expert. Red realized his absolute strength, and instead of staying the Champion, completely public as if he were flaunting his status as the strongest trainer, he set himself aside as yet another, truly final test for those aspiring to become better than him. In my opinion, that's not arrogance, that is brilliant. He made HIMSELF and his Team a test for people to overcome once they had beaten the Pokémon League. That kind of atmosphere is just daunting and epic at its core.
And, of course, this is the reason I prefer Red over Lance. Both trainers are exceptional, powerful, and deserving of their status. But Red has just that much more to prove he is "the very best, like no one ever was"...and you get to be better than him.
This is Shen, signing off and retaining my status as the one who overexplains opinions in far greater detail than people prefer to read without offering a tl;dr option. Night, folks.
<3 Paired with Dog of Hellsing, mah awesome vampire lady <3
Thanks to Neo Emolga for the banner and Knightblazer for the avatar ^^.