This can be a frustrating question, because there's no obvious right answer. Serrated edges have some performance advantages in slicing some types of materials, and they stay sharp forever. Plain edges are useful for more types of cutting.
I prefer plain edges. They cut more materials better, and can also do finer-cutting that's difficult to do with serrated edges. Also, by sharpening with the right grit, plain edges can approach serrated-edge performance even when slicing tough materials. In addition, even though serrated edges might outslice plain edges, there are times that push-cutting is fastest of all, and only plain edges do push-cutting. For example, my serrated endura is slightly faster than my plain endura for slicing poly rope, but I can actually push-cut my plain endura through the rope faster than either knife can slice it! For an all-around knife, plain edges win for me.
All-serrated, for me, is a specialty setup. Great if I'm going to be cutting very tough stuff all day, and would like the knife to stay sharp forever. Whenever I carry an all-serrated knife, I also carry a plain edge to handle the jobs that serrated doesn't do well.
Some people find partially-serrated to be "best of all worlds". They can fine-cut with the plain part, and cut rough materials with the serrated part. But some people, myself included, find partially-serrated to be "worst of all worlds". I find the resulting shortened plain edge part to be not that useful -- for one example, for something like food prep, a short plain edge followed by a short serrated edge are pretty much useless for many jobs. On the other hand, for anyone who does a lot of slicing, and doesn't understand how to optimize their plain-edge sharpening strategy for great slicing, partially-serrated makes lots of sense to me.
Which edge works best for you is really dependent on what you cut. Of course, it works the other way as well -- if you carry a serrated edge, every job looks like a slicing job. You can do zipper cuts by catching a hook and pulling down.
Over time, your strategy should be to get one kind of blade, then down the line buy the other kind, and see which works best for you.
Joe