are you talking about the video footage of big foot walking? i never heard that one was a fake.
as for ness: they did a special on tlc or one of those networks like it. they showed how easy it was to misinterpret naturally occuring events in the loc.. they showed some footage of the wakes from two boats crossing that looked exactly like some serpent surfacing and diving back down. they also showed a bunch of naturally occuring illusions that the lake can produce. it all has to do with the peat moss. so to answer the question; no, i do not believe in nessie; based on the tlc show and the scientific fact that a creature that size could not survive in that habitat.. i really wish it did exist though, im a fan of cryptozoology.