I'm with Danny.
I've always prefered Nintendo systems over their competitors, for the fun aspects. Nintendo has always intrigued me more with their innovative technologies (every system has brought something to the table that competitors have not until generations later). I like the characters, the games, and the control. The only thing I've ever been disappointed with is Nintendo's 3rd party support.
And please do not call me a fanboy because I have owned and sold the following systems in their respective heydays: Dreamcast, PS1, PS2, XBox, XBox360.
Even though I like to give every competitor a try, Nintendo's the only one that ever really gets me off.