As far as I know, there have been 3 Robins in comic book history. (I’m leaving out the Frank Miller female Robin, as that’s kind of an alternate history Robin. I also guess I could double-check my knowledge, but I’m lazy.)
The first Robin, the Dick Grayson of the ’60s TV show and the movies (Batman and Robin, shudder), is the most well-known and the most popular, judging by how many Batman fans bitched out DC when they replaced the character with Jason Todd in the ’80s. They bitched so much, in fact, that in 1988, DC held a telephone poll to let fans vote whether Todd died in the A Death in the Family storyline.
Believing in the innate kindheartedness of fans, DC whipped up a version where Jason Todd lived.
Also believing in the innate dickishness of fans, DC whipped up a version where Jason Todd died.
Guess which one made the newsstands?
The vote was 5343 for, 5271 against. The ayes had it, and Jason Todd died at the hands of the Joker.
But. In 2005, the character was resurrected; supposedly, the polls had been rigged by a fan who really, really wanted Robin 2 gone. This gave DC an excuse to bring him back. They did this by . . . altering reality.
I won’t go too much into the details here. They hurt my head when I read them the first time, and I’m afraid that if I type/repeat them here, they’ll crash my computer. It is delicate. Let’s just say that reality was altered, Jason Todd came back to life inside his coffin a few years after his death, he dug his way out (this always seems so easy to do, but that last guy I buried, he . . . . Um. Never mind.), and, understandably pissed at Batman for not avenging his death by killing the Joker, started fucking with Bats.
The cartoon Batman: Under the Red Hood is a way better (read: less confusing) retelling of the death and resurrection of Jason Todd, with the voices of Neil Patrick Harris (NPH!) and Jensen Ackles.