SteelCentral AppResponse by Riverbed, previously known as OPNet AppResponse Xpert, is a seriously awesome product.  It’s a physical appliance, that’s dedicated to packet capture, typically from SPAN, RSPAN, ERSPAN sources, and can also be used as a serious Netflow/sFlow/jFlow collector.  It then beautifully analyzes and displays this capture data in myriad ways, some of which are shown below.  It is a supreme network troubleshooting tool.  It’s like Wireshark on steroids – making network troubleshooting simpler, faster, easy to use, accompanied by many forms of graphical representation of network data and important metrics.