If you've seen the 60s show, you might remember Batgirl as Commissoner Gordon's daughter, who imitated Batman independent of him and worked alongside him, although neither knew the other's identity. In the comics, she was similarly independent: sharp, clever and determined, and had a continual flirtation with Dick Grayson, Robin
Batgirl: Year One #3
The Batgirl character was retired in 1988, and in the same year, DC published The Killing Joke, written by Alan Moore, in which the Joker shot Barbara through the spine. The purpose of this shooting, both in continuity and for narrative purposes, was to focus on the effect on Commissioner Gordon and Batman; the Joker never discovered Barbara used to be Batgirl. The Killing Joke was a one-off Batman story, not specifically intended to be part of the main continuity, but became incorporated after it was met with great critical acclaim as a fantastic Batman story. The central theme - whether one bad day is all it takes to send a good man onto a descent into madness - was picked up by the recent movie The Dark Knight, albeit with a different man as the Joker's object, and with the opposite conclusion to the question.
Batman: The Killing Joke
The next year, in the DC title Suicide Squad, written by John Ostrander and Kim Yale, a character called Oracle appeared - a genius level hacker who helps the team out anonymously, as a computer hacker and information broker. A few years later it was revealed that this was Barbara herself, who had decided she wanted to get back into the superhero business, and so was determined to use the skills she hadn't lost when the Joker shot her: her photographic memory, superlative tactics, computer expertise and years of experience as a librarian.
Birds of Prey #59
In the Birds of Prey series, created by Chuck Dixon and later written by Gail Simone and current writer Tony Bedard, Barbara runs and operates her own all-female team, snarkily titled by one of its members (Huntress) as the "Broken Superheroine Club". After a disastrous start with Powergirl (an alternate version of Supergirl), the real first operative of this team was Dinah Lance - the Black Canary. At the same time that Barbara was recovering from a bullet in her spine, Dinah lost her superpowers (a sonic scream) when she was tortured by drug runners in the 1988 Green Arrow story The Longbow Hunters. While the in-character motivation was to more focused on Dinah and her actions, the story itself was as much focused around her boyfriend Green Arrow as The Killing Joke had been about Jim Gordon. The two women's histories were aligned, if not exactly parallel, in the timing of these incidents and the emotional problems that followed. Dinah was still able bodied, but she had lost an ability she had relied on, and part of Barbara's motivation in choosing her as Oracle's representative in the physical world, was that she believed she could provide a direction and purpose the older woman lacked since the break up with the (also recently deceased) Green Arrow.
Black-Canary Oracle: Birds of Prey
Oracle's primary strength is her tremendous mental capacity and information skills, but she's also a proficient martial artist. Even though her techniques have changed since she lost the use of her legs, she's more than capable with eksrima sticks, and keeps her body in great shape. She consistently shows great determination and strength of character and is an indispensable resource for, not just her own team, but both the Justice teams and the entire Bat family.
Birds of Prey #111
Writers have on more than one occasion debated giving her back the use of her legs - there's no doubt the agency exists in the DC verse, and Barbara herself would certainly not turn it down - but she remains such a great character as Oracle, and one of the very few decent, sympathetic and complex disabled characters in any fictional format, that I think it would be a loss, not to the DC fictional world, but to DC comics and to the storytelling arts as a whole.
Dead Tree reading:
The Killing Joke by Alan Moore and Brian Bolland
Batman: The Greatest Stories Ever Told vol. 2
Birds of Prey by Chuck Dixon, Gail Simone and various artists
On the internet:
Barbara Gordon on Wikipedia
Oracle on the Comic Book Database.
nevermore999 on Barbara Gordon: Part OnePart Two
TV Shows on DVD:
Birds of Prey