Which development conference should I have my work send me to?

My work gives me the opportunity to go to any one conference in the US each year. Last year I went to reinvent which was really awesome, but I was hoping to try a different one this year. I am a developer of Scala, node and php within our current tech stack. So I do a bit more development than devops and would love a really good dev conference, but there are just so many. Any you guys would recommend?