I like Jennifer Connelly a lot too; first time I saw her in Labyrinth, I fell in love with her

and then I caught Rocketeer. Since then, I have not had the opportunity of watching her other movies so I can't tell how good she is in her craft.
Basically I like actors and actresses who perform well and retain a lot of mystique (this means no dramatics or concocted stories in real life and would eliminate a good number of the thespians these days).
Audrey Hepburn is my favourite actress, even if she has passed away.