I see a lot of Manic Pixie Dream Girl lists but no Manic Pixie Dream Boy lists, so here's a start.

Since the archetype is rare in a romantic setting, I've included both straight-played examples and those deconstructed to varying degrees. Ultimately derived from prototypical embodiments in popular romance and fantasy novels such as Rhett Butler or Peter Pan, and even further back to the princes and cherubs of folk tales, the MPDB is an impossible paragon of security and nonchalance which--in real life--only seems to manifest as sociopathy in the extremely rich and naivety in the extremely young. Somewhat related to the adventure bro archetype but to avoid splitting hairs I'm not addressing histrionic bromances, no Depp, Pitt, or Downey Jr. here. I'm also sticking to heteronormative examples because the distinction is a lot clearer here than in gay romance where the line between fantastical mania and run-of-the-mill histrionics is blurry.

General rules of thumb for identifying a Manic Pixie Dream Boy:

1) Is the male's story primarily concerning the pursuit of a single woman? He might have ambitions secondary to the main romance but they are largely nominal or inconsequential if addressed at all. He may even lack much of a character beyond generally pleasant interests and an inexplicably generous nature. This is easiest to spot in male leads due to the extra attention and scrutiny they invite, and more difficult to nail down in supporting roles that are deliberately unimportant and underdeveloped. In either case, he will be the impelling force during most of the relationship; the girl is just along for the ride, comfortably escorted past all the milestones.

2) Does his courtship involve multiple expressions of a magical, eccentric, or overdramatic nature? Once in any film is just a grand gesture, twice might be excused as a self-reference; but multiple instances necessarily wraps the relationship in an aura of the fantastic. The MPDB and his victim are swept away on the fictions of true love and happy endings, forgetting that this abandonment of reality also removes the relationship from any gravity or catharsis.

3) The female love interest may be a Mary Sue. While the dimensionality of the female lead doesn't directly influence that of the male love interest, there is an interesting correlation between the two. The writer of one lazy character is highly likely to write other lazy characters, especially when the clear goal of their work is vicarious wish fulfillment rather than social commentary. The only substantial difference, then, would be that a POV lead is intended to act as an all-around pleasing self-substitute while a romantic interest is intended to be an all-around pleasing other-substitute. Hence, the lead opposite a MPDB will frequently be an inoffensively pretty girl with minimal, generalized, and ill-defined strengths or flaws like a love of reading or social awkwardness. A blank slate with only the slightest of introvert coding, ready to be swept off her feet and taught how to live.

On the one hand, the MPDB can be viewed as an egalitarian response to the MPDG, off-setting the frequent representation of women as personless extensions of male leads by creating an equally objectified spear counterpart.

On the other hand, the claim of "balanced representation" here, manufacturing an equally sexist female gaze, is spurious, given that the final result is not overall improved gender parity, but doubled inaccuracies in media representation and cultural perception.

And, on yet another hand, the offloading of agency onto a vaguely characterized yet endlessly encouraging figure does nothing to foster realistic relationship expectations in viewers, male or female. The perpetuation of either of these archetypes merely elevates the amount of entitlement with which people approach relationships.

If romantic pulp must exist, it might as well be fair. But it is a shame to see such widespread acceptance for cheap escapism. Do your future husband/wife a favor and stop drooling over these impossibly infectious characters--or better yet, try a hand at becoming one yourself.

As always, any recommendations are appreciated.