My experience is limited, and I travel mostly for mainstream work with a little fun thrown in where I can fit it - so I'm not sure if my opinion should be weighed as heavily as some other ladies.
Boston is ultra awesome, my boys treat me so well
London is my second favorite, although I met most everyone I see there in other cities initially, and was basically just invited to follow them home! DC is nice too. I love San Francisco so much as a city, I have a man that treats me well there, and I barely even noticed that he's the only one, lol.
Least favorite has to be Jackson MS. I have to go there for business, and there is nothing pleasurable about the place. I have exactly one man I see there, and Jackson is quite a trek for him, he keeps trying to convince me to try New Orleans. Second least favorite is NYC. Not the quantity, but the quality - and that is not to reflect negatively on my men (they are worth the hassle, which is why I go back). Just the inconvenience of securing a mediocre "5 star" hotel room that in any other city would have been a broom closet, being forever incredulous as to how long it takes a $10 cab to get several blocks that I could have walked easily for free if it weren't for my 5" heels, and having to brush it all off and make an elegant entrance even though the sidewalk outside smells like something my dog would like to roll in.
Places of ambivalence - Chicago. I have people and places I like there, but generally nothing I look forward to enough to leave Boston for, aside from a change of scenery. The road between Boston and Albany is much more enticing to me than the end goal. I've met more people *from* LA than I have *in* LA... but really the same could be said for most of the cities I mentioned.
~Mme X~