Would be nice if speechcraft and disposition were just beefed up all together. The system was pretty lame in both Morrowind and Oblivion.
Would be nice if a person's disposition would go up and down depending on what type of person you appear to be, and dependent on what you are wearing. Each piece of armor/clothing could have a (or multiple) category/ies that gauges it as lavish, crude, or modest based on how much it costs, and each person in the game could have a similar classification that defines what sort of person/people they like (once again, they can have multiple). The player's strength and endurance would add a multiplier effect to crude apparel (intimidation value), the players personality (along with it's normal disposition multipliers) would add a multiplier to fancy apparel since it makes you look handsome/beautiful/dignified, and the players Willpower would multiply their "modest" effect. Infamy would be considered crude, and fame would be considered lavish; so infamy to crude people would raise their disposition, and fame to lavish people would raise their disposition.
So for instance, if you have a lot of fame, and were wearing ebony heavy armor (very lavish) and were to walk up to an obnoxious beggar (he only likes crude people) naturally he'd like you less from the start and your speechcraft attempts would probably just piss him off; he'd reply with stuff like
"Who do you think you are" and "So you think you are better than me?" On the other hand, if you try to intimidate and rough him up, he'd be more susceptible to that since you "look" like you are better than him
Now, if you were to walk up to that beggar wearing cheap leather armor, and you had a lot of infamy, he'd like you since you'd come off as a crude/lowbrow person. Any speechcraft attempts would likely go quite well since you appear to have stuff in common, but intimidation would likely have less effect since he'd become upset since he thought you liked him and he thought you were friends.
If you were to walk up to some snobby "better than thou" rich person wearing rags on yourself and you had a lot of infamy, naturally this high roller would dislike you from the start, and would despise any small talk you try to make with him. He'd say stuff like "Don't spew your filth at me" or "I don't converse with thugs." But since you are crude and thuggish in appearance, intimidation would work quite well on him.
Of course, there would be some people that have two or three favored personality types. For instance, a scumbag and corrupt rich person who likes both lavish personas
and thugs, and then there could be lower middle class (crude and modest) and upper middle class (modest and lavish) who will like you depending on what type of person you come off as.
TL;DR:
NPC's disposition and the success of speechcraft/intimidation/bribery would be based on how they see you, and certain character attributes, and what you are wearing modifies the chances of certain things working on them depending on what kind of company they like to have around. A snobby rich person would like to have other pretty-faced high rollers converse with them, so expensive clothing, strong personality and heroic tales of grandeur would make them like you. A scumbag street merchant will like tough lowbrow company around him and will like to hear tales of your misdeeds, and will like people wearing crude clothing or armor. Modest people will be equally susceptible to both the extremes, but will have best relations with people who come off to them as normal/middle class and strong-willed. Then there are "hybrid" type people who will like multiple personality types. rather than a lame--ass minigame, there'd just be a few speechcraft options like: Intimidate, Tale of Fame, Tale of Infamy, Converse, and Bribe, and depending on what type of stuff the NPC likes certain things will work much better than others.
Also, this time there should probably be a limit to how much you can speechcraft somebody in one sitting. it doesn't make much sense that you can bribe somebody like 50 times in a row, or admire them like 20 times.