Mostly I think Deadpool's problem is his fans. He really never should have moved beyond the comics, in hindsight. No, I don't care how much Ryan Reynolds fits the role. He's a guilty pleasure for most of us and realistically speaking he's really only at his best when he's teamed with a proper, serious hero. Slipping him in with Cable was a brilliant move to me. Cable needed some levity since, well....it's Cable.
As far as the Robins go, I should probably point out that they do serve a purpose. More than once a Robin has moved into being a hero in his or her own right. Nightwing and Red Robin are two of the most obvious. Red Hood could also be clumped into this category after a fashion as well.
Superman...honestly, people get far too tied up in his physical capabilities. Yes, he can do absurd things and stop almost any threat. Sure. However there also ways to hurt the man very badly beyond the usual kryptonite/red solar-rays business. Focusing on the physical aspect you miss a long procession of writers and artists who have made it their business to break the Man of Steel and push his boundaries. Watch Superman vs. the Elite for an example. Kingdom Come, Last Son, Red Son, doubtless there are others. Hell, if you want a surprisingly good take on physically destroying the man, try All-Star Superman. Luthor's final scheme was...surprisingly good, and surprisingly effective.
Anyway....on topic:
Honestly speaking, I think I'd get rid of the Watchmen. All of them. Entire Book. Gone. Why? Because while it is indeed good, and it's an interesting take on how Superheroes COULD be, a lot of people take it as how superheroes SHOULD be. Yes, realistically speaking these are the types of people we'd have being heroes in the real world. People pushed into it, people with costume fetishes, moral extremists, blah blah blah. Yes, I get it. It's got a broad ring of truth to it, there's no denying that. But it's not how all heroes should be. Some? Yes. It's worthwhile to remind people on occasion of the absurdity of these figures. But there is NO need to hold everything up to that standard. Superheroes ARE NOT REAL. That is WHY you read them. Watchmen comes along and suddenly everyone forgets that. They don't all need to be realistic, yet some people will SCREAM for it. They'll flail and gnash their teeth and cry about it. Superheroes are a FANTASY. It's no different than Lord of the Rings or Harry Potter. None of it exists. Why are we making a point to demand Superheroes be realistic?
There is a difference, however, between demanding realism, and expanding a world and speculating. At least to me. When a friend of mine and I sit around at lunch and speculate on how a Pokemon Center can function, offering free services including food and lodgings, without some kind of revenue, we're not demanding an explanation be put into the games, anime, manga, or whatever. We're just exploring the possibilities. Whining that Superman is too unrealistic or that Captain America represents outdated values (welcome to the party! you're late!), is just annoying. People have explored those things already. They have revealed those flaws. There's no need to keep throwing a tantrum about it when not only have the issues been addressed, it's FICTION anyway. There's no NEED to throw so much reality into those characters.
Watchmen is good. It's a good read and I enjoy re-reading it from time to time. But people take it too seriously and they try and use it to force-feed realism into a medium that doesn't have it in the first place. Either people need to stop this crap, or Watchmen needs to disappear.