I know this one has been mentioned before, currently for example in the green cave quest the wood things will throw entangles at you but you'll be lucky if you even have to save once even when standing amoungst the vines.
The spells should be rescripted to at least make everything in range save ONCE as the spell first appears in the area.
Probably isnt possible to make things save as they enter the area later though, so pulsed tests like they are now would be fine (though they should be increased in rapidity a little)
the exception to this seems to be the gag cloud spam in the smelly sewers. Those always seem to be making people make plenty of saves.