Yeah, I think what Cam meant by "breed" was the whole process, including raising the babies to adulthood.
Another fish not mentioned is the Jewel cichlid, which is also (in my experience) insanely easy to breed. At one point I had a 4 foot tank with two pairs of breeding convicts in it and they'd each claimed half the tank as territory. I put four jewels in and they weren't allowed to deviate from the exact of the tank, the convicts were that controlling - but, after being in the tank for a few days, they actually spawned too, right there on the underside of a log in the exact middle of the tank. I sucked the convict and jewel eggs out and raised them all together, it was pretty cool.
sharn, you say some people think convicts are hard to breed - have they ever even kept a male and a female together before? Seriously, I've never heard anyone say that before, the most common problem I hear is people not being able to stop them breeding. I work at Jansens, and even when we get them in at 4-5cm, they breed after like a day of being in our tanks.