Let's get one thing out of the way right off the bat -- I hate Quicksilver. To me, Quicksilver isn't even a character. He's a shameles rip-off of The Flash, and everyone knows it. And he isn't even a GOOD rip-off, because he's not nearly as powerful or interesting as the Flash.
He can't time-travel, or vibrate through walls. He doesn't store his uniform in a ring. He doesn't own a Cosmic Treadmill. He's never had the feeling that he's been turned into a puppet. And he doesn't have his own TV show. Let's face it, Quicksilver is the favorite character of no one!
But, be all that as it may, Quicksilver is still a superhero speedster, so we're compelled to discuss his origin as part of our "Secret Origins of the Super Speedsters" series. Quicksilver made his inauspicious debut in X-MEN #4, as a member of the Brotherhood of Evil Mutants...
made his inauspicious debut in X-MEN #2
Pietro and Wanda joined the team in Avengers #16, "the start of a great new Avengers line-up!" Cover below by Jack King Kirby.
A few pages from the story...
BELOW: From AVENGERS #75, April 1970, perhaps Quicksilver's finest moment in modern times, courtesy of cover artist John Buscema.
BELOW: Quicksilver as he appears in Avengers 2: Age of Ultron.