I generally agree with the top-voted answer that fake meats should just be avoided by and large (I feel like much of the perceived ickiness factor that omnis have of veg foods comes from these (often poorly-done) substitutions), but, for personal consumption, when you've got a hankering and anything that even asymptotically approaches the real thing, I suppose they do.
That said, I like using TVP (textured vegetable protein) to make quick taco filling and in spagehtti sauce, chili etc. I get it super-cheap from the bulk section of a local natural food store, and it makes for really quick recipes. e.g. dump a cup of TVP in a tupperware container with some taco seasoning; pour a cup of boiling water over top; mix, put lid on tupperware; wait 5-10 mins. You've got taco filling.
Similarly, one can reconstitute TVP and then mix into spaghetti sauce for a faux bolognease.
These tend to be things I eat a lot of when I'm cooking just for myself and am on a budget (I can get a pound of (dried) TVP for ~$2, which, since TVP is super light, makes a ton!)