Ah, Gamespy. Once upon a time, their server listings and client were the be-all-and-end-all of PC multiplayer (ever since the original Quake, as I recall) while even numerous console games relied on their infrastructure over the last few years. However, they'll be shutting up shop as of next month.
Many games have already made alternative arrangements well ahead of time, so will not be affected, but even a cursory examination of the hundreds of games that used the service brings back fond memories; everything from Serious Sam to Red Dead Redemption and Mario Kart Wii.
Gamespy pulls the plug on May 31st. Any memories you'd like to share - or are you happy to be shot of it?