In Poland:
-extra 2 weeks of holiday sponsored by the company (not much sponsored though, around 400 EUR);
-discounted tickets for Lot Airlines (return prices are: Europe 30$ + taxes, World 60$ + taxes, domestic 15$ + taxes), although they are stand-by tickets with no reservation. Considering the amount of LCC nowadays it's not a big deal.
CSA gives completely free standby tickets for Poles (and obviously for Czech ATCOs- maybe for the rest of us also?).
Oh, that's it.
Few years ago we got a book on 40th anniversary of the Company, could be the same aim as in Heathrow