Cone-ann, e.g. the Schwarzenegger films,
or
Koh-nin, like “ronin,” e.g. Conan O’Brien
?
Koh-nan.
Another for Koh-nan
Aside: Is this the weekend of the pronunciation threads or what?
As if I was explaining that a goat was included. Co-nan
I prefer KOH-nahn. Only in English (and sometimes in French) does A make the sound as in cat. And only English would use the schwa (KOH-nuhn) or neutral I (KOH-nin).
I used to say it like O’Brien
but then when I actually watched the movies, they say koh-nan, so I had to change. A slow, reluctant change, but I did it eventually. Also my friends said koh-nan so I couldn’t be the only one doing it wrong
Other: koʊnən/Koh-nən.
I used to pronounce it as in the movies, but after reading the stories and discovering that Howard intended Conan to be a proto-Welshman, I trained myself to say it the other way.
Random language note: “Conan” is Hebrew for “disk drive”, as in, “I’m going to defrag Conan D.”
Koh-nan the Baa-baa-ee-Anne (as in Barbara Ann)
Koh-nan
If he were a proto-Welshman, it would Kenan (Modern Cynan). “Kün-ahn” is closest. Conan is for proto-Bretons (modern Konan, kohn-ahn). Depending on how proto, it’s a straight-up U if you go back far enough. The Irish name is related.
The Barbarian to me is Cone-Ann.
If you don’t know the answer, he will cast you out of Valhalla and laugh at you.
The barbarian is Koh-nan. The talk show guy is Koh-nin. These are indisputable, as we have canonical evidence to support each. When Conan O’Brien got his first hosting job and nobody knew who he was, they made it quite clear that his name was not pronounced like the movie character’s name. Other people named Conan may pronounce it however they want, but these two are not in doubt.
Ko nahn.
If it’s the Schwarzenegger movies, it’s Coh-nann. Otherwise, and in the REH stories, it’s Coh-nun, like O’Brien.
If it is a random Irishman I’ve just met, I’ll assume it is pronounced Connen until told otherwise.
Yes, but a random Irishman won’t flash his blue eyes and cleave you asunder with his might sinews if you mispronounce his name. 
Koh-nan