While there are a couple of companies (such as The Program Exchange) that do have a publicly available list of the programs that they syndicate, you're not really going to find a comprehensive list.
The closest you are going to come is to just look at the schedules of stations that carry a lot of classic programming, such as KDOC in LA, the local version of ME-TV in Chicago, KFWD in Dallas/Fort Worth, and KADL in Detroit. But recognize that it's going to be constantly changing, as programs are pulled in and out of syndication depending on the level of interest from local stations.