They all look good. to me. And haidee, yours looks just like one of mine I found in the field in my old ancestral home in China.
Fake ones usually have something else written on it. Plus, the background is textured (like small little boils) and the coin just looks very new and... well, recently made.
Also, as not a deterrent, there are steel cash coins. Well, iron cash coins. They we making those up to the 1800s.
Well, I think these are what they're *supposed* to look like.
Anyways, the left one is Daoguang (1820-1850); the middle is Kangxi (1661-1722) and the last one is iron...