The Hardest Catch

[Zayphora]

In terms of non legends it'd be a Gloom from that one island in Platinum. GYAHHH I HAAAATE MOONLIGHT!!!!

Legendaries for me'd be Mewtwo, in SS, i used my master on lugia and had to catch it in an ultra.

and Ho-oh also on SS. I still haven't caught that thing. Keeps comitting suicide with Struggle.

 

[Plasmette]

Mespirit in Pearl. In a stroke of stupidity, it used Toxic on it. (I was a little kid back when I did this). I couldn't keep it in battle, because it would die. IT JUST WOULDN'T GET IN THE DAMN BALL. It was holding me up for YEARS. AND I MEAN YEARS! I COULDN'T CATCH IT.
I just said "Screw it". USed that action replay and got 999x master balls.

 

[WasSollDas]

Ditto......

Accidentally made it transform into Quilava. Took about 20 pokeballs untill I ragequit. :(

 

[Plusleminun]

Cobalion, I used false swipe so it's HP got low.. and 40 ultra and a few timer balls later I had my Cobalion. :)

Kyurem was also extremely hard because it kept fainting itself with struggle. T.T

My fiancée on the other hand, caught Cobalion with a quick ball, and Kuyrem with one ultra ball. O.O

 

[BluDodge]

Either Kyurem in White or Zapdos in Yellow. Kyurem took around 30 Ultra Balls, with at least 5HP. I got my revenge on him though, I named him Dickwad. Zapdos took probably the same amount, all of them "missing" until I used 1 great ball, and got him :P