Best quality setting: (assuming you have Compressor)
Send to Compressor ..
h.264 codec, .mov filetype.
Video compress to "automatic" on Best quality.
Audio set to AAC Variable bitrate Best quality.
I use this when going for best quality compressed, you can always just export media and choose "current settings" to get uncompressed video and audio but it takes up a lot more space and is no good for video sharing sites like YouTube; I would recommend the above Compressor 4 settings.