My favorite hunting Parker is my Dad's VH but it won't be going out any more until it gets new barrels. My newest favorite is a GHE, which did well with the roosters this fall for the few times I got out. I have yet to try an underlifter 12 but that will happen next season. Then the question gets tougher, hammerless or hammer?
Ultimately, the favorite is the one in hand in the field (could even be a semi-auto somethin' or other

). For me, my newest anything is 1970 and oldest is 1881. Oldest anything shot is Win Mod 94 octagon from 1899 and accounted for one buck mulie and one bull moose with almost factory iron sights (front sight blade had been lost along the way and replaced with a penny shaped and filed to fit by a DIY guy). Oldest shotgun to take birds is Parker VH from 1901 - tight as a fiddle with 28" barrels. Took my best rooster in recent memory on a desperate second shot at 50+ yards. Very DOA. Has made me take shots I would never have bothered with in the past. I'll be shooting some of those inedible clay birds this year and will try a few guns. Maybe I'll find one favorite or maybe I'll have a commitment crisis and be unable to settle down with just one.
Cheers
Jack