Virtually all chordates are sentient, and many invertebrates; I've always understood sentient as meaning "able to feel."
There are other animals I'd probably call sapient--namely elephants, dolphins, chimps, bonobos, and probably some other apes. These animals are
pretty close to humanity in terms of raw intelligence.
But it's probably more worthwile to have a spectrum of sapience, rather than a bright-line. A good number of complex eukaryotes have the capacity for taking in and analyzing sensory information from its environment, but at the distant end of the spectrum, they're more like computers than humans. I would not eat my computer, of course, but that's because I keep my porn on there; the average fish has no such porn-archiving function, and hence is valuable as a food source.
On the closer end, you have animals that do seem to have an inner life and self-awareness, as well as emotional response.
Animals that have a certain threshold level of intelligence, I try to not kill. Accordingly, I don't eat any mammals or cephalopods, and although the issue hasn't come up, I wouldn't eat ravens or parrots. The upshot is I can't eat pepperoni and salami anymore. Let alone delicious long pig on jaunts abroad.
Now, I do still eat cheese and milk, because--and vegans should be aware of this--the main reason cows still walk this Earth, or at least this continent, is because they are economically valuable to us. I would not have much faith in the survival prospects of a feral population of cows. It's arguable whether imprisoning and exploiting them is better than extinction, of course.