Geeky 
x264 Video encoding is perhaps the best OpenSource compression utility without degrading video playback quality. The graphical interfaces (GUIs) available out there in my view seriously handicap of what x264 can really do. Of coarse one needs to learn a bit of encoding syntax but once learned you can encode all of your videos to ~half the size without losing your precious quality. One must however realise that this encoding is extremely time consuming & without necessary logging & automation x264 encoding may not prove trivial enough for...
