Which type of convergent boundary creates the tallest mountains?
The type of convergent boundaries is not the only factor. From the current configuration of the world one could be tempted to say that Continental-Continental collisions would form the tallest mountains. And they are indeed the most dramatic tectonic collisions and they formed the Himalayas, that are almost 2,000 m taller than any other mountain on Earth. However, the india-Asia collision wasn't any collision it was the most dramatic collision in a long time with convergence rates of 16 cm/year, way more than any current convergence rate. From USGS
Therefore, the convergence rate is also a very important factor. The tallest mountain outside the Himalayas is mount Aconcagua in an oceanic-continental boundary. With a convergence rate of about 6 cm/year, and that have been below 16 cm/year at least for the last 22 million years. So it is difficult to say how tall would be Mount Aconcagua if you speed up the convergence rate between Nazca and South America plates by 260%.
I don't think there is a definite answer to your question, unless you constrain other factors, like convergence rate, plates thicknesses, etc.