When saying that a deer exhibit is exciting, I usually judge that by which species of deer are in that exhibit and the rarity of that species, for example here are some exhibits that I heard of
San Diego Zoo 1970s, a mixed exhibit with two species of deer, one antelope species, and one bird species, that exhibit consisted of
Zebra duiker
Red brocket
Reeves muntjac
and
Wattled crane
Los Angeles Zoo 1980s, a mixed exhibit with one deer species and one caprid species, the species were
Japanese serow
and
Reeves muntjac
As somebody else mentioned, Woburn has a great collection, but back in the day it was superb and looked like it consisted of more than 20 species including rare ones like Kashmir stags
IMO another exciting deer exhibit is Faunia Madrid, they have the last Gray brockets in captivity outside of Latin America, so people in Spain are blessed because like I said, there are no Gray brockets outside of Latin America besides the ones in Madrid
Even here in Los Angeles I think we have an exciting deer exhibit, that is because we are only one of 3 zoos outside of the Philippines to have Calamian deer
Until 2010 Lima Zoo in Peru had a pretty exciting exhibit, because until 2010 they had the last North andean huemul in captivity
Even Northwest Trek is pretty exciting not just because of naturalistic exhibits but because of two of there species which are pretty rare, those species are Barren ground caribou and Black tailed deer
Although its not really thought of as exciting, I even feel delighted when visiting the Orange County Zoo because we have Mule deer and those are not very common in captivity
Another interesting deer exhibit is Xcaret Park in Mexico, they have the only Yucatan brown brockets in captivity
Another one was Alberta Game Farm, they had some unique Caribou/Reindeer subspecies like Osborns, Barren ground, Peary, and even Newfoundland if I remember correctly
Putting species aside, the Coues white tailed deer exhibit at the Arizona Sonora Desert Museum is pretty spectacular because it looks frighteningly similar to their natural habitat and plus Coues white tailed deer are a pretty rare and interesting subspecies of Odocoileus virginianus
Anyways I could go on and on