The important goal is to provide motivation, to convey the breadth and the beauty of a subject and interdependency between different subjects. I doubt this is possible with emphasis on algebra in an atmosphere of pending high-stakes examinations. Algebra, in the high school scope, is a collection of skills potentially useful to various degrees depending on the profession chosen. Other subjects should be considered as motivation builders. And the one that naturally comes to mind is geometry.
Geometry is more visual and more palpable than algebra.
Geometry is often used to help introduce and explain algebraic concepts. Geometry is rich in structures, patterns and interrelations. And nowadays, technology makes geometric explorations more accessible and more intuitive. The following page brings together the notions of discontinuous functions, altitudes and medians, similar triangles, iterative processes, and the Star of David.