Properties of Gamma Function - Detailed proof of G(p+1)=p G(p) 17 minute video
Normal Density Integrates to 1 - 13 minutes.
Elementary explanation of Gamma Function without proofs - Note that (1/2)!=G(3/2)=(1/2)G(1/2) = sqrt(pi)/2
(urdu/hindi) Properties of Gamma Function - 30 minute video.