Once I was playing late at night on Pokemon Pearl and I went into the old house in Eterna Forest and An old man floated across the screen. for some reason I was creeped out!

Once I Was Playing Platinum the i was walking around and i swear i saw a gayrados in the water that had a pikachu cry

omg the old guy in the house happened to me too
once i had a dream about darkrai driving a bus lol

i had a dialga that was both genders!!!

i was bateling someone in pokemon heartgold and my Fearow randomly fell asleep. XD

How come your fearow fell asleep like that warriorpeeps?

I was playing pokemon Blue when I ran into a glitch pokemon called Missingo.It was a huge static blob and had a cry that sounded like all the crys put together...It messed up my game

I got lost in Turnback cave... and apparently found myself circling it about 3x just to go to the distortion world to find the griseous orb (90 rooms)
(and like azumarill's answer)
and then I fell asleep and got a dream where Shaymin(female) made out with Giratina(male) and then Arceus(female) kicked Shaymin off the Hall of Origin because she said that Giratina was her boyfriend (note: they were in their human personas)

And when I bred my Arceus and Giratina, they had bred a bad egg... only to remember that i had pokesav so i didn't save teh game (I exited when I saw the egg hatch into bad egg)

I also had one of my Pokemon randomly fall asleep while i was walking through the Enterna's Old Mansion, the Pokemon that did that was my Level 100 Empoleon. So far it hasn't happen twice, Maybe because i never walked into the Mansion again.

God my Empoleon cant land a hit on a Level 28 Bibarel what gives