Retired English Teacher
Are the sentences below natural? Thank you.
1. This was the most unforgettable trip of my life.
2. This was the most unforgettable trip in my life.
In my opinion 1 is more natural than 2, but only in this particular usage. There are other usages in which 2 would be preferable, e.g. this is the best time I've ever had in my life.