These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Sentry
Alas, Poor Scrappy: Subverted. Writers attempted this with his death in Siege, but they accompanied it with an enormous of amount of Character Shilling (on top what he was already given) with everyone saying how much better off they are because of him, despite his most noticeable accomplishment being nearly destroying the Earth and being useless as a hero.
CanonGod-Mode Sue: One of the reasons the fans hated him. He could defeat almost everybody in the Marvel Universe, from Iron Man to Galactus, going by Carnage. And he couldn't die, to the point even complete disintegration barely slowed him down.
Creator's Pet: Writers love using him, fans hate seeing him. If they wanted to see Superman with mental problems, they would've just gone to Superdickery.
The Good News: He's finally dead! The Bad News: despite being utterly useless for most of his comics existence and a Face-Heel Turn that also revealed he was an Eldritch Abomination and saw him try to destroy the world, his send-off issue was nothing but the entire cast of Marvelverse heroes waxing poetic about how wonderful he was and how he'd made their lives better in flashback retcons. The hamfisted attempt at Alas, Poor Scrappy was not well-received.
Rogue had sex with him first, despite the fact that was established in the pages of Xtreme X-Men that Rogue lost her virginity to Gambit when the two lost their powers.
He's also an example of a God-Mode Sue. He's better at molecular manipulation than Molecule Man , for instance (it is debatable as to whether this was the Sentry or the Void, an issue even further complicated by the fact that no one really knows what the hell either of them are). All this may come with the territory, given that he's heavily implied to be Death and all that...
He's a perfect example of an interesting character/idea turned into a walking plot device.
Mary Sue: A violent Deconstruction; the Sentry actually is the Bob's self-imagined idealized version of himself. The result is... well... not as great as you might expect.
He was actually well-received initially due to his interesting origins and that he had a cool fight with the Green Scar in World War Hulk, but when different writers got a hold of him, they started going crazy with his powers, skyrocketing them (take note that he couldn't beat the Green Scar), and making him immortal unless he wants to die, and despite the above, a massive amount of Character Shilling.