i always leave my solid state gear on all the time. some amps are basically designed to be left on as its better for internal parts to be on all the time vs being turned off.
some will say that they system doesnt sound right if the system has been turned off for a while and took xx amount of time to sound like it normally does.
since you have already got a 50/50 split on answers and sure you will get more replies on this....you may have to experiment yourself on this.
only time you should not only turn off, but also unplug everything is if you are going to be on vacation / out of town for a while and cant be there as never know when bad weather or something could happen. that applies to other electronics as well that are in the house.
