I'll have you know that I'm a legendary beast-master!

I remember back when I was playing Ruby, before I inflicted damage or status on groudon, I just tossed a pokeball at him and then it clicked and I caught him. I was so excited when it happened. :P

Zekrom in White was the first non-Master ball legendary that I caught under 15 minutes. I have horrible luck!

Mewtwo in pokemon red, back in the day. just wondered what would happen if i just threw a regualar pokeball right away when the battle started. Well ill be damned, it caught the bugger!

Cobalion, unsure of the catch rate, but Ultra Balls were the ball of choice. Only took a couple. That moment made me happy because I was prepared to turn my game off and on until I got him with Ultra Balls. Lol

My fastest catch was Tornadus in Black, quick ball first encounter.
I also caught a Mewtwo with a master ball in FireRed.