To go along with the letters and numbers :)

. , - ! ? ' " ( ) : ;

What else?

good idea :D

to add to your list, maybe interrobang (?! or !?)

An ellipses! ...

And an asterisk! *

And maybe an ampersand! &

Yes! This would be awesome! :D Maybe # and + as well.

Though it's not technically punctuation, a tilde would be nice~

I agree with this! I'd love to be able to make something like :3, : D, or : ) on my sticker album!

Personally, I'd also like to see < and >. For <3 and stuff like "ME > YOU" or something similar.

Maybe a tilde, carrot, plus sign, and forward/backward slashes?

~ ^ + /

And Spanish opening interrogation and exclamation signs, too! (¡,¿)

These all sound like awesome ideas, I would definitely want to buy those kinds of stickers.