i'm a "head-turner," and often get whistles and catcalls, etc. and NO, i'm not conceited - it's a fact. my daughters get a total kick out of it, and have a "theme song" for this behaviour ... they sing, "mom's milkshake brings all the boys to the yard..." whenever i get catcalled. the dance that goes with it is hilarious.
anyway, as other ladies stated, it depends on the guy - but not so fast! even if he's a hot, well-built 22-y.o well-dressed abercrombie model, if his actions creepy and leery then it's just disgusting and disrespectful. when an older (60s-70s) unwashed homeless dude makes a comment but is polite about it, it's sweet!
most preferred behaviour ... a guy notices me, doesn't make a verbal comment, doesn't leer and ogle, but has a prolonged, polite stare. then when i notice him, he SMILES as he makes eye contact ... and then looks away. maybe glances back, but just glances. no winking (that's so TACKY!!!) or any other gesture.