Sorry, tried many of them, disliked all of them.
Non-nagios experts are NOT qualified to mess with nagios setup period. To let anyone just define a host and leave out it's parent, etc, will make the status map like one big mess, showing the nagios process in the middle, with 200 hosts all connected to it. When in fact, that host(ftp server) has an interface card, that card is connected to a switch port, that port is on a switch, that switch is connected to ..... and so on.
Nope, not while I"m here. I've already trained about 6 people and they configure and maintain there own portion of the network.
The gui tools are no good for experts either, since they force you type all the information by hand.
With vi, I simply do a 6yy, p, change a couple words/numbers, and I'm done. I can configure about 10 hosts in the time a gui tool can do 3, maybe.