This thread, must be the funniest one yet
But I felt the need to contribute my intellectual view on this very important query.
There is only one ICO, and it's the Initial Coin Offering! So whether you pronounce it as "ai-co" or "ai-cee-oh", people who are involved or know about the cryptoworld, would definitely know what your talking about. So no worries!
The funny thing is that if you google this question you will see that people actually wonder how it's pronounced.