I remember seeing the little rainbow-coloured Apple logo on a friend's computer when I was like 12. Back then I had no clue I wanted to be a designer, and didn't know one iota of anything about computers, but I remember I liked the shape of the logo. #1.
I've always liked the Apple logo. When I got older, and Apple came out with the Clamshell MacBooks and blueberry eMacs, it bumped up their image in my mind since IBM, HP, Compaq and Dell were all making ugly black and grey things. I admired them doing something different, even though I still really didn't know the difference in software. #2.
Then, when I saw the Wall•E-ish (you know the ones) iMac I was sold on Apple design. Kind of like seeing some really cute or hot blonde and then - Lo! - she turns out to be the nicest person with lots in common - it started with looks. I fell in love with the PowerBook G4 and lusted after one for years. Since buying my own Mac, and having now experienced both iMac and MacBook Pro (well, and an old Performa from work, that still chugged on like a champ) I'm sold on both quality of hardware and software. #3.