When a person is Intubated the person is given general anesthesia and a muscle relaxing medication to prevent any pain and discomfort from the Intubation.
However some people have experienced a slight discomfort when they are Intubated but it's not really bad.
If it's a real emergency where you will need to be Intubated then you may be Intubated while awake but if it's that serious then the pain is the least of the worries because without Intubation you could die.
So I would take some pain of the Intubation over dying.
Intubation is an Invasive procedure so it's normal for some discomfort or pain to be experienced sometimes.
Most times a person is asleep when Intubated though so it's not too painful.