Germany, some of the more popular stations...

ZDF - http://module.zdf.de/teletext/master.html

Das Erste - http://www.ard-text.de/

RTL - http://www.ard-text.de/

ProSieben - https://www.sevenonemedia.de/teletext-viewer

Not a bad way to brush up on my German actually ;)

Further reading:

http://www.giga.de/webapps/ard-hd-live-stream/specials/telet...

https://en.wikipedia.org/wiki/Television_in_Germany#Channels