I like history and travel so would enjoy receiving postcards showing:
-- People, especially those representing traditional cultures
-- Illustrations/works of art from your country.
-- Historic sites and monuments,UNESCO sites
-- Landscapes, gardens or city/town views from your country
-- Vintage cards
-- Pre-history -- dinosaurs, cave paintings, etc.
-- Wildlife and birds from your area
-- Inge Löök postcards
-- Fun, whimsical postcards (Jetoy cats for example)
I don't enjoy advertising cards -- but like most other kinds of postcards. Interesting stamps are always appreciated.