Good or free. You can only choose one.
that's a pretty silly statement considering paint.net exists
what specific features would you like
less restricted video editing (e.g, movie maker only lets you cut in certain amounts iirc), multiple audio tracks, sound importing, exporting in mp4, and not having exported videos take up a gb for 2 minutes is really what i really would want, anything else is sorta just extras
http://www.nchsoftware.com/videopad/
shotcut
I use shotcut personally. Its free and has lots of great features.