There's a lot of good, cheap FD glass out there, not all of which says "Canon" on it. I'm not generally a big fan of zooms, but I picked up a Kiron 80-200/4 for practically nothing, and it turns out to be absolutely surgically sharp. Keep an eye on the "non-manufacturer zooms" section at KEH; a lot of stuff goes through there, sometimes extremely cheap.

Some of the Vivitar Series I lenses are supposed to be excellent as well, though I can't testify personally.