I don't mind effeminate guys, aslong as they're not overly obnoxious/ loudmouthed and gossipy/dramatic, etc. But that has nothing to do with gender roles and everything to do with a conflict of personality. I just can't identify with people like that, male or female, beyond as a source of temporary amusement at their (imo) absurd antics. Luckily most, in my experience, aren't like this at all.
I like guys who are in touch with their emotions, though, and aren't preoccupied with traditional gender roles. I'm not, and I tend to view myself as more "neuter" in terms of gender identity than as distinctly "male" or "female," and I appreciate others that feel the same. I generally view myself as more of a "submissive" type, and generally prefer someone a bit more dominant than myself (but not that much, as I am ruthlessly individualistic, as well, just not always the most forthright or decisive, so I really don't like domineering or parental-seeming fellows) but I can just as easily get infatuated with someone who doesn't necessarily have those characteristics. I just have to be able to see some traits or insight I can respect. Confidence and willfullness (traditionally viewed as "male") or emotional understanding and thoughtfulness (traditonally viewed as "female,") both are admirable traits, and it doesn't really matter to me, much, aslong as they possess traits I can admire strongly, and speak to my personal view of the world (which is essentially a mixture of "female" and "male" gender identity, anyways.)
Then again, it's hard to discern what is meant by "effeminate." I may be completely misreading the point of this thread, as it isn't always the easiest to assign characteristics that consitute "male" and "female," etc. Limp wristed sissy boys seem more a product of immaturity or shallowness than any distinctly "feminine" characteristic, IMO, although their is often a sense of femininity coming from their mannerisms. An immaturely masculine guy would be just as annoying, IMO.