I think my favourites are the New world monkeys / Platyrrhines but out of the multitude of species that inhabit the Neotropical region it would very hard to choose a favourite. I suppose mine would be either the buffy tufted marmoset ( I have a huge interest in the Callitrichidae) or the muriqui for both sentimental and scientific reasons.
There are so many to choose from, but the snub-nosed monkeys and tassel-ear marmosets are high up on the list for me.
My favorites are lion-tailed macaques. I also like white-faced Capuchins (I've seen them in the wild) howler monkeys (also seen them on the wild) and a variety of black and white colobus monkeys. Hopefully I'll see some of those in the wild this summer.
Toque macaque, Cat Ba langur, Red-eared guenon, That beautiful grey langur @Chlidonias saw in India But in a comfortable first place: Golden snub-nosed monkey
Restricting it to those I have seen: Angolan Colobus Purple-faced Langur Black Lion Tamarin Crowned Guenon Bolivian Night Monkey Of these the langur is my favourite by far
I like them all, but my personal favourites are snub-nosed monkeys. I find the Golden spp. the more attractive-looking species, but Tonkin snub-nosed monkeys have really strange and funny faces too so it would be a toss up between them. I think this preference was cemented by the excellent Planet Earth II.
There are so many different species of monkey that I found it impossible to choose just one but, restricting the list to species I've seen, my favourites would be: proboscis monkey golden snub-nosed monkey red uakari Hamlyn's owl-face guenon Allen's swamp monkey
I’ll follow @TeaLovingDave ’s lead and restrict myself to ten species I’ve seen: Proboscis monkey Black lion tamarin Mandrill Red-shanked douc Red-faced spider monkey Heck’s macaque King colobus Golden-bellied mangabey Drill Owl-faced monkey Closely followed by black howler monkey, pied tamarin, gelada, Diana monkey, southern pig-tailed macaque, Barbary macaque, dusky langur, white-throated capuchin and red-backed bearded saki. I also love Javan surili, golden snub-nosed monkey, black-and-white tassel-ear marmoset and red uakari but as I haven’t seen them yet they’re not in the list
My favorite monkeys...well, I can only think of two at the moment. 1. Red-Shanked Douc Langur - I love the coloration on these monkeys. 2. Golden Snub-Nosed Monkey - again, the color on these guys never fails to amaze me.