I am pretty sure I am in the minority on this one but for me the end was far from perfect. Don't get me wrong, I still loved the movie but I didn't like the fact that Woody was an "old family toy" but yet they just give him away at the end? It just sort of rubbed me the wrong way. So the toy has been passed down to them, but now they just don't care since toy story 2? Wouldn't they want to pass it down to Andys or Mollys kids? For me a perfect ending would have been Andy's kid getting the toys somehow.
As far as toy story 4 goes, as long as it can live up to first 3 then I'm all for it. If we end up with another cars 2 then no thanks.