The Great Giana Sisters was a favorite among two of my sisters (the third one wasn't intersted in games), but Winter Games on the C64 was really the favourite game for my youngest sister. She have later tried various winter sport games on the PS2, but she says it isn't the same because she liked the sheer simplicity of Winter Games with the joystick waggling and all.
My impression is that girls in the 80's & early 90's usually liked games that weren't too violent and not too complicated (meaning they were easy to get into), a high cuteness factor of the games often helped a lot as well. At this point in time I didn't know any girls who had their own computer or console, they usually borrewed them from their brother(s) instead, and I remember that even though my sisters wasn't allowed to, they used to sneak into my room when I wasn't there to play games on my C64 & Amiga.
But this was of course back then, nowadays my impression is that asking what games girls prefer is the same as asking what games guys prefer - the answers will vary a lot in both cases.
