***Load*** and ***[loads][1]*** work just as well as *bunch*.

 - There's a *load* of water
 - There are *loads* of books on your desk
 - There's a load of books to carry
 - I had to study *loads* before my exams
 - Save *loads* of money on your car insurance

And even more colloquial is the expression *[**shitload**][2]* to describe an impressive quantity of something.

 - That's a **shitload** of sweets (BrEng)/candies (AmEng)
 - I have **shitloads** to do


  [1]: http://www.thefreedictionary.com/loads
  [2]: http://www.merriam-webster.com/dictionary/shitload