I prefer the toned look for myself. I've been working out for something like 4 years, and have gained a total of maybe 8-10 pounds. Part of it is my metabolism and medium-sized frame, but the rest is just that I honestly don't want to gain much weight. I'm a freak when it comes to my own health and diet. I'm at roughly 8% bf right now, and I still feel like I could lose a pound or so around my midsection.
As for which is harder: well, it depends on the person. Generally, I'd say getting toned requires more discipline. But forcing yourself to eat enough to become bulky can, for some people, be quite an accomplishment in and of itself. Besides that, bulking also requires some serious lifting.
And as for women and what they prefer: first of, for most women, physical appearance (and especially body) isn't as important as it is with most men. The ones that I've spoken to actually vary quite widely (as with men) on what they like. A few liked their men to be chubby, some liked them skinny, and the majority wanted them somewhere in between: toned, but with some bulk so that the woman feels slightly overshadowed by her partner.
In terms of body parts, I've met girls that like them all, but generally the favorites seem to be: chest, stomach, shoulders, arms, butt, and hands. Usually a woman will like two or three of the above in lieu of the rest.
Just my own experiences, though. By no means an ultra-authoritative reprepsentation of all womankind.