I don't think i remember the third film in this franchise. Was it good, was it bad? I don't know but i know this one would sort of make up for it. As far as Sequels and Trilogies go, they start to become a bore after a while (except Harry Potter but...). 4th films always end up reminding us why the franchise is so recognizable. This movie does just that.
After facing a near midlife crises with his new family, Shrek makes a deal with Rumpelstiltskin to be an ogre for only one day with the price of taking away one day of his childhood. But of course as all fairy tales go, there's a catch. Rumpelstiltskin takes away the day Shrek was born and poof, he becomes king. Shrek appears and tries to reverse the contract with (well we all know) true loves kiss.
This movie in particular has many laughs and pop culture refrences that wiuld make parents laugh more then kids, but then again isn't what made Shrek so good was it's originaity? Still i believe that this franchise continues to grow on that and hopefully this wont be the final chapter of this great movie series.