Philosophía
"The devil made me do it"
I put prep and intelligence in the same category -- yes, you can be smart but not have big resources to prep, but you can aquire them if needed. That said, in terms of forum fights, prep is one of those things you kind of need some leeway from the person you're talking to in order to actually have a discussion -- especially once you move away from the Reed/Doom/Batman's of the world who have a variety of prep-tech/feats to choose from against a multitude of abilities and types of characters.
In comics the way it usually works is:
"How does Doom counter Magneto?" Well, he has anti-electromagnetic Magneto prep. Ok.
"How does Lex Luthor counter Martian Manhunter?" Well, it just so happens that he has prepped to negate both telepathy and shapeshifting from Martian Manhunter. Ok.
"How does Batman counter Wonder Woman?" Well, he just so happens to have an anti-Wonder Woman lasso. Ok. etc.
But on the forum, if you go "How does Batman counter Thor?", it's generally not accepted to simply say "He's smart and resourceful, he'd make an anti-uru device" or "how does Doom counter Captain Marvel?" to simply say "Oh, he's smart, he'd create something to cut him off from the gods". And we've not even gotten into characters with intelligence/prep that don't have the showings the top ones have, where making a case is much harder. In that sense, sometimes prep fights don't dwelve into possibilities, but more into "who built the biggest armor?" or "who created the biggest gun?" -- which kind of makes it overlap with some other categories.
I think speed is the most broken ability -- for most of the items on the list there's some sort of counter, but with speed it's either you have it, or you don't, and the answer to these questions take the answer to a thread towards one extreme or the other. It's moved past even the basic "I not only can not get hit, but I can hit you as many times as I want and you have no ideea the fight has even started" [which is already broken]. Even the extended applications like intangibility, invisibility, infinite-mass punchiness etc.. Now it can also be "You'll fight a nigh-infinite number of time clones and they'll kill you before you even open your eyes at the start of the match. Oh you also have some speed? Let me steal that, too." I know the latter is not really a forum part, only tourney, but the fact that it's an options is absurd.
I think healing factor and durability are nice to survive, but unless you're in a team-setting and you're just there to be used as a shield or whatnot, it's just prolonging the inevitable, unless your opponent has few options or shitty stamina. They're only moderately good in tandem with another ability [like Hulk's strength/healing combo] to make you a tank, but even so it can only take you so far until you come up against somebody with abilities that you simply don't have an answer to when you can't punch [which is rare, but still]. Strength gets you through most of the comic book fights but, as above, you kind of need something more to go along with it for the most complex fights [at least you have to be able to close the distance]. Energy projection/manipulation is pretty great, but most of the time it encounters a 'tank' it gets shitcanned -- I think the potential for bullshit on this is high in terms of what it can allow you to do [see recently Vulcan just pulling "Hulk is Hulk energy is energy" card: https://ibb.co/TM3kZpR -- though his whole thing is that he can manipulate all energy, even magic, so eh] It's good for when you want to get tricky [i.e. manipulating brainwaves or whatever] --but in terms of 'raw' stuff the strength/invulnerability combo mostly allows you to plow through it.
Weapons are good as long as you have them -- I wanted to make a compilation a few years ago of how many times Thor drops Mjolnir when he gets hit in a fight, but I stopped at about 25-30 times since I didn't have the patience to keep going. They leave the character vulnerable in as far as if they get removed [temporarily or not], he's kind of caught with his pants down. But, I think a Green Lantern ring or Mjolnir or whatnot takes you very far on the forum in terms of options, as long as you're proficient with it and don't use it to blast, or bludgeon. Maybe surprisingly I think weapons are generally portrayed as more powerful than characters with the innate abilities sans-weapons [i.e. Mjolnir is more powerful than Surfer, Hal is more powerful than, well, almost everyone etc.], though I'm sure there's counter examples. Sometimes characters with innate abilities are even shown as more vulnerable to losing their power than the ones who have weapons, funnily enough.
Daddy come save me is essentially having other characters fight for you, which is shit. I will ignore it.
So if I had to rank, in comics it's something like:
Strength/Prep [yeah, I know...I'm being generous with prep here]
Weapons/Invulnerability
Energy/Speed
Healing
On the forum [and in terms of how I'd rank to have them in general], it's something like:
Speed
Intelligence/Prep [assuming chars with extensive histories]
Weapons
Energy projection/manipulation
Strength
Healing/Invulnerability
-ish