Take your pick from these:
-I once had Miror B's theme from Colosseum as my ringtone.
-I learned RNG abuse for Gen IV just so I could give my gf a Shiny Luvdisc for her bday (the fact that I gave her a Luvdisc over a better Pokemon may be the reason why she dumped me a few months later).
-I went to a WoW IRC channel several years back (despite not playing the game) just to troll and say that WoW was cancelled. The amount of nerd rage was a glorious sight to behold.
-I got into a drunk fist fight with a friend because he said Bakugan was better than Pokemon and Yu-Gi-Oh
-I fixed up our old family NES as a Xmas eve present and played Duck Hunt, SMB3, Mega Man II, Contra, and Dr. Mario with my sister and her boyfriend (who's now my brother in-law) into Xmas morning.
-I jokingly told my brother "Why don't you make like a tree...and get out of here", then I proceeded to make him watch the Back to the Future trilogy with me when he didn't get the reference.