Tashahhud Du`a - 1 (Hadith No. 794)

There's a list of du`as that can be recited in tashahhud. For your ease, I'm doing one du`a a post.

Volume 1, Book 12, Number 794:
Narrated Shaqlq bin Salama:
'Abdullah said, "Whenever we prayed behind the Prophet we used to recite (in sitting) 'Peace be on Gabriel, Michael, peace be on so and so. Once Allah's Apostle looked back at us and said, 'Allah Himself is As-Salam (Peace), and if anyone of you prays then he should say, At-Tahiyatu lil-lahi wassalawatu wat-taiyibatu. AsSalamu 'alalika aiyuha-n-Nabiyu wa rahmatu-l-lahi wa barakatuhu. As-Salam alaina wa ala ibadil-lah is-salihin. (All the compliments, prayers and good things are due to Allah: peace be on you, O Prophet and Allah's mercy and blessings be on you. Peace be on us an on the true pious slaves of Allah). (If you say that, it will be for all the slaves in the heaven and the earth). Ash-hadu an la-ilaha illa-l-lahu wa ash-hadu anna Muhammadan 'abduhu wa Rasuluhu. (I testify that none has the right to be worshipped but Allah and I also testify that Muhammad is His slave and His Apostle)."

I'm sure you all know this one by heart, and you should! It's mandatory to recite it in tashahhud.

Do keep its translation and meaning in mind while reciting it though. It's really beautiful. AND it has a very interesting story behind it. Who knows it? :)