personally my favorite bp in my collection is a LTC captive normal.

But as people have said already your thought of morph x morph is better in some way isn't true, as many normals will provide a great base if you pick intelligently. For example in my own collection I'd rather outcross with quality normal animals than inbreed a morph into a depression. Besides trying to steer away from inbreeding, I think selective breeding with choice normals as a base is important for a good morph. Plus normals are so variable and amazing...