100mm 2.8 is my favorite. The one I borrow from time to time from a friend is not the IS version. It's a great lens, for macro shooting or otherwise. I use it for weddings all the time.
That being said, I actually used the 50mm compact macro professionally every day for years. I've made more income with that lens than any other, by far. It almost never disappointed – only in its inability to focus super-duper closely from time to time. In those cases, I just backed off and cropped. Big deal for the small shots I needed in the end. I just switched the camera to large jpeg instead of small jpeg for those few and far between shots.
For FD, I like the lens of the same name. Not sure if it is the same optically as the EF version.
You can also adapt many old lenses to your camera. Nikon and Pentax, for example. There are some great manual focus choices for very reasonable prices out there, such as the Nikkor 55mm (http://www.kenrockwell.com/nikon/55f28ais.htm).