Abraham Lincoln suspended habeas corpus and the court ruled that it wasn’t within his authority, I am wondering which President did the most things that the Supreme Court explicitly ruled were unconstitutional, not actions where their constitutionality is questioned by the public but hasn’t be directly ruled against.
FDR, in part, because he was in office the longest, and in part, because the courts early in his Presidency took a crabbed view of what kinds of economic regulation were constitutional that courts later in his Presidency abandoned.
A list of the number of executive orders made by President can be found in this Congressional Research Service report. FDR at 3522 executive orders and an average of 285.64 executive orders per year, is the clear leader by either measure. A general legal overview of this area of law that does not quantify the number held unconstitutional in each administration can be found here. Very granular detail without summaries is available here.
Statutes have been declared unconstitutional by the U.S. Supreme Court a bit fewer than 500 times since 1789 when the current constitution took effect (but any court state or federal can declare a law to be unconstitutional, this power is not reserved to the U.S. Supreme Court in the United States).