The flavor text in the Pokédex paints Shuppet as feeding off of grudges and deceit, in the sense that they remove those emotions. "Victims" of a Shuppet's feeding tend to experience much more pleasant moods for a time afterwards.
Misdreavus feed off of fear, as well, which explains why they like to startle people and scream at them.
From the Pokémon Mystery Dungeon series, the Bittercold, the Big Bad in Gates to Infinity feeds on the negative emotions of all the Pokémon in the world.
An NPC named Unfulfilled-Desire in Planescape: Torment feeds off of desire, and will literally drain you of whatever wants you describe to her. It's apparently quite a disturbing experience, but you can use it to help someone overcome his alcoholism if you know about her beforehand.
In Sonic Unleashed, Dark Gaia gets power from the negative emotions of everyone on Earth. Even though he's basically just a mass of anger and hate, though, he somehow oozes green blood.
The Guardian Lords in the Wild ARMs series are a cross between this and Gods Need Prayer Badly. One of the themes is that since the world is dying, Love, Courage and especially Hope are disappearing and therefore the Guardians of those emotions are doing badly and can't help to fight back. Until our plucky heroes inspire them of course. Desire is doing perfectly fine in the dying world though.
The spinoff Turn-Based Strategy game introduces the opposite of a Guardian, specifically an entity that both feeds off and promotes fear, fitting the trope a bit better.
Demons in Shin Megami Tensei III: Nocturne fit this to a certain extent; it's not the emotions themselves that feed them, but the power that they create, called Magatsuhi. Angels and other lawful demons tend to feed on the Magatsuhi created by adulation and faith, while devils and other chaotic demons tend to feed on the Magatsuhi created by terror and anguish. Make no mistake, however - neitherside is particularly positive.
Nyarlathotep from the Shin Megami Tensei: Persona series also feeds on every single negative emotion of humanity, being the representation of humanity's negative emotions. His rival Philemon, in contrast, represents humanity's positive emotions.
Demons in Dragon Age: Origins fit this to a tee. Desire demons in particular seem to relish the chance to experience mortal life.
Kogasa of Touhou eats surprise. Unfortunately, she's not very good at surprising people. On a wider scale, youkai are at least partly dependent on human fear; the tenuous balance between the Human Village and the youkai is laboriously maintained by Yukari and the most powerful factions.
Hata no Kokoro, the main antagonist of Touhou Shinkirou ~ Hopeless Masquerade, starts to absorb the hope of people around her when she loses her Mask of Hope. While she stopped doing so, she's still capable of eating the emotions of others.
In some Castlevania games, it is stated that Dracula can come back just by absorbing the negative emotions of humans.
Obscure Game Boy Advance game CIMA: The Enemy uses this trope. The eponymous villains are said to feed off of the emotion of hope. To do this they drag humans into an extra-dimensional dungeon where the thought of escape gives them hope.
The Ruina from Super Robot Wars Destiny feeds on negative emotions like despair, hatred, etc. Thus they do everything to ensure the world is in a dark state thus the negative emotions of these humans would be fed on them. And their leader, Perfectio, is... practically immortal.
Hopes frequently comments on the taste of the emotions of various X-Cross members during Vault scenes in Super Robot Wars X. Unlike many examples of the trope, he doesn't actually drain the emotions he eats, but he does rely on their presence for sustenance.
Unlike Hopes, Ende doesn't actually rely on human emotions for sustenance, but likes the taste of them anyway. Also unlike Hopes, he's gluttonous enough to suck them out and leave the victim a soulless husk, and even when he doesn't do that, his favorite emotions are hate, fear, and anguish.
World of Warcraft has the Sha, who feed on whatever negative emotion they (and their offspring) represent. The most powerful Sha, however, doesn't need the emotion to be a negative one. After all, Pride can sometimes be good, and Pride is the most powerful of all seven Sha.
The Pkunk of Star Control II are an interesting inversion. Being a very psychic race, they designed their ships to use psychic energy as a power source. In a fight, they continually insult and trash-talk their opponents, working themselves into a frenzy of psychic rage that feeds their weapons systems. In other words, they have literally weaponized hate.
In The Witcher 3: Wild Hunt, a quest involves saving a nobleman from a monster known as a "hym," which is a demon that feeds off feelings of deep guilt and remorse. In this case, the man in question murdered his brother, and the deep guilt from that drew the hym in and caused it to latch onto his soul and generate "visions" while he slept that he interpreted as the will of unspecified gods. Geralt can either draw the hym out to fight it directly, or trick it into leaving its host to find a new victim to latch onto, with the latter involving a companion fooling Geralt into thinking he murdered a child, then revealing it didn't happen at all, leaving the hym hostless and banishing it.
Investigation of the notes in The Park reveals that Atlantic Island Park itself is one of these. Basically, Nathaniel Winter found out that Solomon Island possesses a vast reservoir of dark power hidden deep beneath its soil; believing that this power source would be able to imbue him with magical abilities and make him immortal, he found that the power could only be unlocked through an influx of emotional energy - ideally positive ones. So, he built an amusement park on Solomon Island, augmenting it with siphoning machines to draw off the joy and happiness of any guests: as a result, people who visit the place end up walking away feeling scared... unless of course you're already experiencing depression or other emotional problems, in which case the park might just drive you insane, hence the massive amounts of murders and suicides that plagued Atlantic Island Park during its time in the spotlight. Main character Lorraine Maillard begins to suffer this particular side-effect herself as the game continues.
Later on in The Secret World proper, it's revealed that as a result of unlocking the power he desired, Winter's been transformed into the Bogeyman - and now feeds directly on human fear.
Cupid: The titular character Cupid, played by Guilleme, is a dark being that feeds on love. According to the game's lore, there are all sorts of ways to extract this from people, including straight up seduction, gaining the admiration of a small town, caring for orphaned children, and even in the epilogues, starting a Twitter fanbase. Another character with the same affliction, feeds on the memory of her dead Mother. The game claims that different kinds of "love" have different "tastes", similar to that of normal human food. Guilleme, also one of the game's big bad is addicted to the seductive kind of love like a drug, and can't stop from consuming it, even though it has destroyed many lives.
Midnight's Favour from Sunless Skies is a sentient plant that eats regret. The dried leaves of the plant apparently makes for an amazing tea, as the tea drinks your pain and regret as you drink the tea.