The Entertainer is actually pretty good. Same access as the Ark member but fewer enforcers and there’s a spare outfit lying around that’s pretty easy to get if you start with a lockpick.
Anyways here are my picks:
The Finish Line:
Street Musician would be my first choice. No difference between that disguise and the suit.
If that one doesn’t count because it’s a joke disguise, I would pick the Sheik. Which only allows you to enter the VIP area of the Thwack paddock. And since the sheik himself is already inthe VIP area you can’t even use the disguise to get inside.
This was a harder choice because every disguise is at least somewhat useful. Eventually I picked the Barman disguise, which gives you access the basement of the bar. Useful to get an Elite Guard disguise but that’s it.
Sure the barman can poison stuff which is always good, but since he hasn’t access to most places it’s usefulness is limited to Contracts Mode. I guess you could poison P-Power’s drink to get his disguise, but why do that when there’s an easier method?
Chasing a Ghost:
Since we’re excluding joke disguises the Holy Man is out. So my choice is the Metal Worker. Which gives you access to one empty apartment and the Crow’s back ally. Not the underground base itself, just the alley. And if you want to bring a weapon with you, you have to sneak into the alley because the guards will frisk you.
The Arkian Robe, due to having the distinct honor of being less useful than the suit. Because for some reasons the Wilsons don’t want to have people in robes at their garden party. For a guy who writes sex novels, Mr. Wilson is awfully judgmental.
If that one, for some reason, counts as a joke disguise I pick James Batty next. Which allows you access to his backyard. Since you need to knock him out for this disguise and there’s only one other NPC around (who I think doesn’t even care about you trespassing) there’s no real a point in using the disguise to blend in.
The Ark Society:
I’ve no idea yet. Probably a waiter of chef. Or maybe the butler because it’s hard to get. Haven’t really experimented around with the disguises in the level that much.