Well, everything about it is great, and it's been a part of my life since I was little (like 3 years old). I guess it's something constant that will always be there, sort of like a safety zone. Plus, it's an amazing universe to explore, whether you just watch the movies, or take in all the books, comic, games, etc.
For me, it's also escapist fantasy. There will always be the mundane parts of life....work.....bills.....problems. SW represents a more exciting place you can go to whenever you want, and forget about your cares. Sort of like Cheers
It's even got John Ratzenberger!