By and large I'm not a serration fan, but a situation came up recently where a serrated blade worked perfectly.
I was out pruning my banana trees. Weird thing about banana trees, you plant one, and 2 years later you have 10! Anyway, banana tree limbs are weird. The limbs themselves are very soft and pulpy; however, they have tough strings running through them. You don't want to have too much of a push-cut component through them, because it crushes the limb.
I started out with a short machete, but sometimes it wouldn't get through the last batch of strings, and would rip the limb. If I did it faster, it'd go all the way through the limb, but then hit another soft pulpy limb that I didn't want to cut.
I switched over to my Leatherman Wave. Plain edge, as sharpened from the factory (unused) didn't work well at all, it had a lot of trouble with the stringy fibers. Sawblade worked okay, but the pulpy limb interfered with how fast it cut, and it left ragged cuts. The serrated blade was the winner by far -- made much smoother cuts than the saw blade, didn't fill up with pulp, and cut through the tough stringy fibers no problem.
Would a high-performance plain edge have worked better than the serrations? I'm not so sure -- my deerhunter fared better but still not as good as the Wave's serrated blade.
So there ya go -- I found a serrated blade application for ya!
Joe