The abstract spatial strategy game Abalone. I first played this at a bachelor's party close to 20 years ago; it wasn't until a business trip to Germany 4-5 years Vor that I picked up a copy for myself.
We just received Trickerion from Kickstarter and couldn't wait to play. This was very much a learning game for us and we did make a couple of mistakes, but we had a blast and highly recommend this game.