Yukari
It depends up to a degree on what selfish is, but in Yukari's case she's chaotic and selfish to an extent.
Chaos:
...Well, what less of an chaos will you get when you think about an youkai who pulls out traffic signs and trains from her gaps, but also the fact that
what she does catches others completely off guard.
Although in a sense you can argue this chaos as being a part of a genius which she is.
Selfishness:
Yukari keeps open the border to the netherworld ever since Perfect Cherry Blossom and you can argue that to be a selfish action, or maybe we don't know her true intentions of those actions.
Even though we get a selfish image of her from actions like these Yukari will always put her self after an incident concerning Gensoukyou, like what happened when the Watatsuki sisters decided to come along.
Kanako
For Kanako, we don't know enough of her to say things for certain but from her actions so far...
Chaotic?:
She may have suddenly appeared in Gensoukyou, taken over a mountain, given a certain stupid crow the power to fuse, and sent her shrine maiden to beat up and free a ancient monk, but all of those actions had purposes. Well, maybe giving the ultimate form of energy to an idiot may have been a bit unexpected, but than again same thing as Yukari. Maybe we don't understand to the full extent of what they have planned for the future.
Thus youcan argue Kanako as a bit chaotic, but not as much as Yukari.
Selfish?:
Bringing her shrine over to Gensoukyou is said to have been for the her as well as for the good of Sanae, and the bringing of nuclear fusion was for the prosperity of the mountain by the technologies that the Kapaa would make from that (Although there are text that we sort of see a technology freak part of her). So in terms of being selfish, she isn't all that selfish if you look at it.
In doujin and second-hand art and all that...:
Yukari would often be portrayed as selfish grann-*SUKIMA*
Er... I mean, a selfish beautiful lady giving Ran and Reimu lots of troubles. Also chaotic as of the ideas that she thinks up.
Kanako is often portrayed as eccentric sort of ideas and actions and follow her own sold codes of rules honers and whatnot.
But this is non official stuff so you can catch this statement wrong once in a while.