I, for one, 

used to say that you think your opinion or action is right, even if others do not:

The Crown 604_I, for one.mp4

The Crown, s6 ep 04- The Queen addresses the nation after the death of Diana, Princess of Wales. - open in new tab

Listen to the speech by Queen Elizabeth II.

Abbot Elementary_205_I, for one.mp4

Abbot Elementary (s2ep05)- open in new tab

One of the primary/elementary school teachers talks to his principal/headteacher. 

Last Tango in Halifax 306_I for one.mp4

Last Tango in Halifax s3 ep6 - open in new tab

This couple are flying from the UK to Australia and New Zealand on a holiday. They are talking about an (extremely wealthy) distant relative the man is not very fond of.