E.M.
We have two kids (2.5 years apart) and we've never regretted it. I was 36 when my second was born, and I'm not saying I didn't occasionally panic about the age thing, but it all turned out okay. I think two kids are fabulous. Just so much fun.
Someone mentioned that two are quadruple the work. That's true sometimes. But--in our family--more often it's less work. They play together a lot and she reads to him. They're just buddies. They even sleep in the same bed. It's hard to imagine that any play group could provide that level of companionship.
Plus, I love my own sister so much. I can't imagine life without her. As our parents age, it's nice to have someone with whom to share that burden.
In the end, I just think that whatever brand of crazy your family sells, it's nice to have someone else who bought it also.