This city makes princess and I very upset (6)
I believe the answer is:
vienna
'this city' is the definition.
(Vienna is an example)
'princess and i very upset' is the wordplay.
'princess' becomes 'Anne' (Princess Anne, daughter of Queen Elizabeth).
'and' says to put letters next to each other.
'very' becomes 'v' (abbreviation).
'upset' is a reversal indicator.
'anne'+'i'+'v'='anneiv'
'anneiv' in reverse letter order is 'VIENNA'.
'makes' acts as a link.
(Other definitions for vienna that I've seen before include "Austria's capital city" , "sort of sausage" , "huge 20 [ULTRAVOX] hit" , "Capital city on the Danube" , "European capital" .)