I've been collecting PC since I was a child, before the Internet!
My favorites are postcards with
architecture of all kinds (churches, temples, castles, etc),
art (paintings, statues, murals),
people (especially in traditional dress),
Interesting stamps are much appreciated.
(I dislike sunsets, cityscapes, silly cards, obscene cards.)
Just so you know, I am not Chinese. I am an American who lives in China. I can only read about 200 characters. Sorry.
Thanks for sending me a PC! :-) Have a blessed day!