In this debate as Pro, I will uphold the resolution, “The Doctrine of Sola Scriptura is unbiblical”. I ask that only a non-Catholic Christian who honestly believes that the doctrine of Sola Scriptura is biblical accept this debate. No devil's advocates please. The burden of proof will be shared.
DEFINITIONS Sola Scriptura: "The Bible is the only infallible rule of faith for Christians." Note: I have attempted to provide a concise definition and this is the best I came up with based on a variety of sources. I invite my opponent to revise this definition as needed in the first round, but please be concise.
Unbiblical: “not in accord with or sanctioned by biblical teaching.” 
I am a definite believer in "sola scriptura." As a Christian who recognizes that I was born again by the word of God, which lives and abides forever (1 Peter 1:23), I most definitely believe that the only infallible rule of faith for believers in Christ is the word of God; the holy scriptures. I agree with your definitions of both terms. Also, to say "only rule" surely means there can be no other source of infallible rule; this I agree with. No magisterial teaching can be infallible, and it cannot conflict with the clear word of God as taught by the Holy Spirit. I am in no way averse to men expounding the scriptures, but men are fallible and can definitely misinterpret scripture or teach false doctrines.
2 Timothy 3:15 tells us that the scriptures themselves are able to make one wise unto salvation and is elucidated in 1 Peter 1:23; we are born again by the very word of God. Romans 10:17 tells us that faith comes by hearing the word of God. Deuteronomy 4:2 and Proverbs 30:6 warn against adding to the word of God, implying that any discrepant word of man is to be rejected and found breaking this command. Against the temptations of the Devil, Jesus referred to the truth of the scripture (Matthew 4:1-11). Jesus also frequently pointed to the scripture authoritatively (Matthew 12:3; 12:5; 21:42; 26:24; Mark 12:24; Luke 10:26; John 5:39). John 12:48 tells us that Christ shall judge us by the very words He has spoken, and if we truly believe all scripture is given by inspiration, or moving of the Holy Spirit within men, then we must believe that we shall be judged by the Book. If Christ shall judge us by His word, then we cannot expect Him to hold us to the various teachings of men, but only that which is contained in the Book. Therefore we must look to the Book, the inspired and preserved word of God, as the final authority in all maters of faith and practice!