For those wondering, I first want to say that there is a brief funny clip after the credit, but I don't think it's worth sticking around for. It has nothing to do with anything really.
I'm surprised by the criticism here. I actually really enjoyed Iron Man 3. I guess I didn't go expecting to see Tony Stark in the Iron Man suit the whole time, though. I will admit that there were many times throughout the movie that things were very unbelievable, but you get that with most movies these days, especially super hero movies. If you don't like watching movies where you have to suspend your disbelief then you probably shouldn't be watching most movies ever made.
The final battle was epic and there was plenty of action throughout. I felt like the story had me engaged the entire time. It felt like they really brought things to a finish at the end though. That doesn't mean there couldn't be another sequel, but I don't think there will be.
I definitely enjoyed the movie and think it was worth my time.