I really like the 45-70 and when the right one (that would be something appealing, practical and within my price range) comes along, I will jump on it. I have an affection for the .375 Winchester as well. It is powerful, well mannered and the 375's I've shot have been plenty accurate for the platform.
Otherwise, I’ve been contented with old, American .30 caliber stand-bys for as long as I can recall. My reloading of those cartridges is equally dis-interesting; I use H4895 in all of them. I do have a passing personal interest in the .223 and a professional interest in the AR/M16 family.
I guess flunked this thread, LOL. Can't pick a favorite.