For me, the biggest turn off in a man is political conservatism, materialism, metrosexualism and American accents.
I suppose that one man's (or woman's) idea of political conservatism will likely be different from the that of the next, particularly given the potential - and often also real - differences between small-c conservatism and big-C Conservatism and even sometimes between different manifestations of the latter, for an example of which one has to look no farther than the UK "Conservative Party" at any given time since WWII and the "Conservative Party" in South Africa. Small-c political conservatism is surely by definition largely a thing of the past in our rapidly changing world, since it identifies itself at least in part as a concept in which resitance to any kind of change features quite highly. Not everyone has the same view of the position of any particular individual "Conservative" on the political spectrum, either; Sorabji, for example, once described Margaret Thatcher as a "pink socialist"...
Materialism has become such a pejorative term for some people that one might almost be forgiven for assuming that it has all but lost any other credible connotation; for me, materialism of sorts is OK up to a point, provided that it is kept firmly in its proper place at all times and that its importance in the overall scheme of things in life is never inflated - rather like the computer, which is an undeniably useful tool but which some people allow to take over a disproportionate amount of their lives. I have no problem in principel with the business of acquiring and maintaining reasonable degrees of financial wealth per se, but when an acquisitive attitude towards wealth and its visible trappings begins to get out of proportion and interfere with anyone's healthy attitude to life in general it becomes counter-productive, dangerous and potentially disgusting. It is also a mistaken assumption on the part of some people, however that those possessed of immense wealth are invariably interested only in one-way traffic - i.e. towards themselves. I was once introduced to a person (who is no longer alive) whose personal fortune was publicly estimated (rightly or wrongly I neither know nor care) as more than one-seventh of that of Mr William Gates; he lived relatively modestly and, over a considerable period of time, devoted substantial amounts of his wealth to philanthropic activity without advertising that fact.
"Metrosexualism" - rather like the even more bizarrely contrived mixed-language term "übersexualism" - is such a revolting concept that I'm not surprised that you find anyone espousing it a turn-off. One of the reasons for its unedifying nature is perhaps that it is in itself one of the many-too-many inventions of the sociopsychological fraternity that has been picked up and run with by the marketing and PR fraternity, each of which groups seem heavily populated by people who love little better than to pat themselves smugly on the backs for their perceived cleverness in "classifying" people and putting them conveniently in neatly labelled pigeon-holes. The usually less than reliable and often rather tiresome Wikipedia has an entry which is at least a serviceable definition at
https://en.wikipedia.org/wiki/MetrosexualYour take on American accents - assuming (until and unless corrected) that you mean the accents of ALL English-speaking Americans when speaking (or attempting to speak) English (or what they believe is English) - may seem like abit of a shame (in principle, at least) for those many millions of American males who come into that category but, in the end, it's just a matter of personal taste, of course - and there's no arguing with that!.
Turn on: French accents, Scottish accents 
intelligence, moral integrity and artistic temperaments. I like someone who doesn't take themselves too seriously and who isn't perfect.
French accents - eh, bien sur! - although, again, do you mean ALL French accents? - Parisian, Marseillais, Bordelais? What about those of French-speaking West African and Mauritian people? And - dare I even mention it(?!) - what about les Québecois?...
Scottish accents? Ah, I had one of those once, before I emigrated to what some French superciliously call "nord Normande" (i.e. England); I do wish I could remember precisely where I accidentally left it. Actually, in all seriousness, I probably lost it more rapidly than otherwise I might have done because what I had acquired by the end of my time living in my native country was an accent that some Scots might have called "hybridised Hibernian" and that one Englishman once actually did call "hotch-potch Scotch", by reason of my having lived in various parts of Scotland where the accents differ quite widely from place to place. Your mention of it après reference to French accents reminds me of a curious experience I once had when in Paris 18 years ago for a performance of one of Sorabji's piano works (by an Australian pianist, as it happens); it was a Sunday and the performance was scheduled to commence at 4.00 p.m., so I strolled into a restaurant and ordered lunch in my really terrible faltering French, whereupon the waiter rushed across to the Maître d' and said "il est écossais, écossais!" and I received service, in very good English, which was beyond exemplary in efficiency and politeness throughout. Now I know that, in general terms, the French have more affection for the Scots than they do for the English, but quite how this waiter, who had never previously met me, picked up on an accent that I once possessed but had long since lost I have less than no idea.
Intelligence, moral integrity and artistic temperaments are all virtues well worth having.
One can be of very serious disposition without necessarily taking oneself too seriously.
No one is perfect!
Like elspeth, I can't stand helicopters (hoverers) or limpets (clingy types).
Do you (and/or "elspeth") have other such colloquial classification terms for males? (just curious); maybe you (singular or plural) should consider publishing a list here!
Best,
Alistair
Topic: The opposite sex