Out of curiosity, what side of the 'moral' scale do you think Wario usually falls on in his games? I mean, he's always a better person than the villains he goes up against (with the possible half exception of Captain Syrup), but is he an anti hero or a villain in terms of personality and actions?
TV Tropes lists him on both the anti hero and evil vs evil pages:
In Brawl I would consider Wario just a villain (until the end of Subspace Emissary where he's in the cutscenes to be funny).
In the Wario Land games Wario should be considered an anti hero.
The way Wario started as a villain in the GB games sure he did steal a castle and the commercial for SML2 had Wario look like a villain, but in actuality Wario looks so silly and although he looks a little mental he's also really innocent. He copies Mario's power ups for what? To show he (Wario) is just as violent as Mario. You move your feet you lose your... castle (all it is, is conquest). I don't even know how Mario lost his castle in the first place. And that is the only time I ever see Wario as a real villain besides Brawl where he collects trophies of the playable characters (the closest thing you can get to killing).
But looking at the anti-hero Deadpool, he does some pretty messed up stuff too for laughs. So considering all the bad things Wario has done, he really isn't that bad but is rather an anti hero.