Sorry I'm not giving you much to go on. Busy day. PNG, PhotoJPEG, Motion JPEG are all good codecs for near master quality. PhotoJPEG at 75% is a sweet spot. PNG can have an alpha channel.
Then there are downloadable codecs. Look into Apple ProRes 422 to see if it suits your needs. If you want to send out compressed videos for viewing rather than for further editing or compositing work, H.264 is great and is compatible with Flash in some forms.
The linked site has always been great for a description and some understanding of codecs, although it's getting dated by now.
http://codecs.onerivermedia.com/