That moment when you've got a nice long chain going (for once) and then a Bidoof comes in and wrecks it. That is ALWAYS a wtf moment. I don't even like Bidoof.
And when I had Pokemon with ID numbers ending in everything except 2 and 5, and every single time I got a lottery ticket, it ended in - you guessed it - a 2 or a 5.
Yesterday, I was battling Palmer and almost won, if my Mesprit had attacked first, I would have. WTF.
When I was playing Gold and caught a shiny Geodude, and the next day, I saw another shiny Geodude in Pearl. By the way, shiny Graveler looks like a dookie. What the...ah, never mind.
And that stupid save function where if you don't delete your old save file beforehand, you can't save a new one. This especially sucks when you catch a shiny Steelix and then can't even keep it. WTF!!! >.<