I'd have to go with Tappestry of Nations as my favorite old parade and SpectroMagic for my favorite new parade. Tied for second would be the Stars and Cars Motor Parade and the Main Street Electrical Parade.
It has to be the Tapestry of Nations for me, simply for the music. Out of the newer parades though I guess I enjoy Spectromagic the most, but who wouldn't enjoy that?