Getting my Darkrai and starting my Event Collection!
My absolute best experience has got to be when I managed to get Darkrai! I had originally heard of the movie coming out, alongside the Eigakan Darkrai Event, and I just fell in love with the darn thing! xD
I spent an entire summer trying to find someone to trade it. Due to searching for someone to trade, I noticed most people would only do so for Events, so that's how I slowly started my Event collection. Then when I actually got that blessed Darkrai, not only was I absolutely ecstatic, he also became my first ever EV Trained Pokémon!