What signs are Pisces most compatible with?

Cancer

but frankly its not about signs compatibility instead its only and only about relationship and trust compatibility.

Any relation which is compatible on the basis of signs cant continue for long until and unless there is trust in it.

So, its my suggestion to u that do not look for signs compatibility rather look for trustworthy and loving relation.

As its said - "People look for the perfect person to love, they fail to realise that a person becomes perfect when you Begin to love them sincerely."