GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
NetWorx - NetWorx is a simple and powerful tool that helps you objectively evaluate your bandwidth situation.
trafficWatcher - trafficWatcher is a small tool to monitor your network activity.