Assuming by "it all," you mean "a big ol' D."
Women really want a big ol' D.
Hoping to determine the effect of penis size on the perceived attractiveness of potential mates, researchers at the Australian National University recruited a population of 105 Australian women (mean age: 26, aka, The Meanest Age), and asked them to indicate which of 49 computer-generated figures they most wanted to fuck by rating the figures' sexual attractiveness on a scale of 1-7.
Like real men, the figures were life-sized. Each one varied in three traits: height, shoulder-to-hip ratio, and the size of their (flaccid) D.
In news that will serve as a real ego boost for hot guys, women tended to prefer the hot guys to the less hot ones. Tall figures with broad shoulders and narrow hips (a body type NBC News likens to that of an Olympic swimmer—Jeah!) were routinely ranked as the most attractive.
When researchers controlled for those extra sexy variables, they found that having a big ol' D (which is to say: large in overall length and girth) was extremely important in determining attractiveness; nearly as much as height. Attractiveness increased linearly with D size until the CGI D reached 3 inches. After that point, perceived attractiveness continued to grow as size increased, but less drastically.
Interestingly, a big ol' D was found to be most important for tall men. Researcher Brian Mautz speculated to NBC News that this is because tall men require "a disproportionately larger penis" to look like they have a big one. (In other words, what looks like a big ol' D on a guy who's 5'7 will look like a normal ol' D on a guy who's 6'2.)
The researchers believe that, in the era before clothing began hiding D's from public view, a female preference for big ol' D's "could have driven the evolution of larger penises in humans."
(Humans' D's are the biggest of any primate's relative to body size.)
(So even if you have a little D, there's always that.)