[edit] not sure does this even qualify as a 'board game' but here it is anyways [/edit]
Codenames:
nothing really to do with (spy) theme -- it's a word game.
Roughly:
a bunch of word cards are displayed on the table.
There's two or more teams, each with a 'spymaster'.
With two team, (almost) half the word cards belong to each team. Only the spymaster knows which cards -- they have to give their team clues, if their team correctly guesses the related words, the cards are covered/marked with the team colour.
It took us a round or two before we got into the game -- and into the way of thinking of the spymaster. It was very enjoyable -- our spymaster was pretty adventerous at times with the clues which made it interesting. Note: one clue can be used for multiple cards. (Spymaster states how many cards.)
Playing in German was helpful: you can string words together to make new words. (We didnt inspect the rules too closely to see if this allowed.)
The spymaster's view with three teams playing:

(whoever guesses the dark card by mistake loses instantly)
image from this review:
http://www.theboardg...s-party-game-review/