For trips of modest length I can't imagine buying specialty bars, or at least the few times I've looked they seem quite expensive. Generally what's in the cereal aisle at my grocery store is fine. For a thru-hike, I'll stock up on a few things at a Costco, and in that case sometimes get a few dozen "special hiking bars" of some sort in a big carton at not too much money per bar, but I've not been a big fan of those I've tried thus far (quite limited selection).
In agreement with a previous poster, I also am not fond of Lara bars, and I'm not big on Cliff either (though I don't know all the varieties). Power bars are okay, I guess (just expensive). I recall un-fondly a sort of very high protein bar with an attractive and tasty chocolate outer, but the heavy protein core was something that I eventually got so that I just couldn't stomach (and that's saying something when you're thru-hiking ...).
I really don't get the whole special bar and special electrolyte (or whatever) drink powders and such; it does seem to me to be at least in part a triumph of marketing. I do quite fine with grocery store granola bars and crystal light drink powder.
I mean no disrespect (nor wish to start any argument with !) those that do find value, it's just how I see it FWIW. I guess another way to say it is that I try to get sufficient nutrition from various foods that having special bars or special goo or whatever doesn't seem necessary. Who knows, maybe I'm missing the boat here and would become super hiker if properly fueled!