On servers I find atop to actually be a better tool for finding issues that happen incrementally and not an obvious issue. I think that atop and htop both are very complimentary.

http://www.atoptool.nl/

"Atop is an ASCII full-screen performance monitor for Linux that is capable of reporting the activity of all processes (even if processes have finished during the interval), daily logging of system and process activity for long-term analysis, highlighting overloaded system resources by using colors, etc. At regular intervals, it shows system-level activity related to the CPU, memory, swap, disks (including LVM) and network layers, and for every process (and thread) it shows e.g. the CPU utilization, memory growth, disk utilization, priority, username, state, and exit code. In combination with the optional kernel module netatop, it even shows network activity per process/thread."