I'm not sure what my favorite visual Sci-Fi is, but I think my favorite all time Sci-Fi book is I, Robot by Isaac Asimov. My 5th grade English teacher read that to us in class, and I had to go out and buy my own copy. I reread it every couple of years.
I got started young- Dad got me hooked on Star Trek when I was three and my first movie in the theater was Star Wars. Best part: passing it on to my daughter. She ditched spending time with me because Enterprise was on and she always watches that with her dad.