Over the past five seasons of the hit ABC reality show "Shark Tank," countless entrepreneurs have pitched their products to some of the world's most influential investors.

Not only do contestants have a shot to convince billionaire investor Mark Cuban or real-estate mogul Barbara Corcoran to fork over a few hundred grand, but they do so in front of a national audience of about seven million viewers.

Some aspiring entrepreneurs have risen to the challenge and shown how to give a pitch that's so concise and effective that the investors feel like they'd be missing out on some major cash if they didn't gain a stake in the company.

In anticipation of the sixth season's two-hour premiere on Friday, Sept. 26, and with the help of Andrew Figgins, a Chicago-based entrepreneur and owner of the fan site InTheSharkTank.com, we look back at some of the greatest pitches we've seen so far on "Shark Tank."

Vivian Giang contributed to this article.