Here are the Bahnsen debates that I could find on the internet for free:

R.C. Sproul vs Bahnsen:

Dr. Bahnsen vs Dr. Stein:

Bahnsen vs Smith:

Bahnsen Lectures at Westminster:

Part 1:

Part 2:

Part 3:

Part 4:

Worldviews in Conflict:

Part 1:

Part 2: