Actually. the correct phrase would be "The schools that I like". Use "that" for a restrictive clause - you are describing a restricted part of all schools - the schools that you like. Use which on a non-restrictive clause. "The school, which has a great language program, is the one that I like. "The schools where I like" is just wrong by itself. It would be correct if a verb and clause are added. "The schools where I would like to go are mostly in the East."

which The schools I like... Now that is the best.

The first is correct.

The school which I like is correct.