On the quest for a Full Stack Application Performance Management Tool

I am on the quest for a top-notch Full Stack Application Performance Management Tool that can deliver deep dive diagnostics and diverse monitoring of our application environments, frameworks, code, databases, availability, uptime and error alerting/reporting.

"trends at a glance – from page load times, to error rates, slow transactions, and a list of servers running the app."

We are using New Relic at the moment and are quite satisfied with their solution.

Nontheless, for our upcoming project I would like to hear some alternatives/recommendations (incl. pros/cons) for comparable (or even better) tools.

Thanks in advance.

ps. please substantiate your opinion.