Best free video editor (or best cheapest editor)

woud recommend looking into open source/free alternatives first before getting commercial software.

one that have found through a search via wikipedia is a project belonging to the VLC developers- http://trac.videolan.org/vlmc/ -its the vlmc movie creator,is completely free-in both GNU criteria and monetary value.
its in early development,but looks very promising from the screen shots-
http://trac.videolan.org/vlmc/wiki/Screenshots

another one off the same list that is free and worth a download-
http://www.jahshaka.com/ -problem is its quite an old version so may not work without some sort of issue,but its always worth a try,they are bringing out a new version in a matter of weeks they say.

here are the wikipedia links to look through:
http://en.wikipedia.org/wiki/List_of_video_editing_software
http://en.wikipedia.org/wiki/List_of_free_and_open_source_software_packages#Video_editing

to be honest,the linux operating system wins hands down on the amount of video editing software available,dont know if woud be interested in setting up a dual boot or virtual machine [virtual box is well supported and free] to use linux and get the best of both worlds.