DaVinci Resolve is available for free(beta) without ads, watermarks and full save and export capabilities are included. Only the pro plugins and effects are not included.
Revolutionary tools for editing, visual effects, motion graphics, color correction and audio post production, all in a single application! (Free)
available for Mac OSX Windows and Linux.
Whilst Davinci Resolve (beta, free) can produce HOLYWOOD quality videos, it can be very hardware demanding (8-16GB RAM, i5 CPU or equivalent and a decent video card)