Which mega zoom is better?

you should consider why you want such a zoom and what other, more important, features would serve you better. Bear in mind that a 3x zoom has been shown to cover more than 90% of shooting situations. Beyond that, Panasonic is not a camera company, I would avoid them. I like Olympus and use Olympus DSLR cameras, but I would not buy an olympus point and shoot since they use the xD card. It's more expensive compared to SD and others. Nikon is a quality most know and trust. Fuji is under rated in my opinion. I would go with the Fuji. You get plenty of features and value.