It depends how much you like amusement parks. If you've been to Disneyland Paris, Disneyland California is very similar. Knott's is nice because it is truly a "theme park," the theme being American History, especially the Old West. In general, the rides are about the same level of thrill as Disneyland. If you want more roller coasters, go to Six Flags Magic Mountain, also in the L.A. area.