If you've been to either, which if your favorite.
Put me down for Knott's Berry Farm. Besides having my #1 coaster Ghostrider and dozens of other great classic rides, they have the best food, theming, atmosphere, lanscaping, friendliest staff, everything! Just a well rounded beautiful park. I'm constantly comparing it to Busch Gardens Williamsburg since they offer the same level of quality throughout the park in everything they do, and in some cases, even surpass Busch.
Six Flags Magic Mountain - I love most of the coasters, but then that's where it ends. They've placed so much emphasis on just adding coaster after coaster(and not all of them that good), that the rest of the park has been seriously neglected and needs alot of work. All the things I said about Knott's are complete opposites at SFMM. Can't wait to ride Goliath though, but even so, SFMM will still be a very hollow park without much sole. If you were to take away the coasters, your not left with much else, and a great park in my book needs to offer more than just coasters. Just my opinion.