There are a lot of things that can inhibit PCR
You might find the Alkami PCR Guide helpful, but I don't think they have a comprehensive list:
Some common things that can inhibit PCR are excess EDTA, NaCl, SDS or other detergent, and any phenol or ethanol. There's also stuff that can precipitate with your DNA during extraction (like proteins and polysaccharides) that will inhibit your PCR. People also have problems with inhibition from DNA samples from feces, blood, soil, and formalin fixed samples, among others.
Do you have a specific problem with inhibition, or were you looking for general information?