While there have been a few exceptions, almost every girlfriend that I have had, from my teenage years until I married my wife (including my wife), has been very petite, with a girlish figure, and a moderately-to-very athletic build.
As mentioned in other posts, in the long run, personality/compatibility is much more important than just wanting to have a woman's body because of nothing more than initial (mostly visual) sexual attraction. As such, I did have a few very good relationships with taller, fuller-figured (hour-glass curves), larger-breasted women.
But, for me, there is also more to wanting a petite woman with an athletic build. I enjoy athletics and outdoor activities. And, I find a like-minded woman/girlfriend/wife to be very attractive. I love sharing my active lifestyle with "my woman" (hiking, horseback riding, camping, jogging, swimming, skiing (snow & water), working out, etc, etc, etc). So, while I will admit that I find petite small-breasted women to be visually/sexually attractive, there is more to it than just what I desire to see, touch/hold, and suckle when I take their clothes off.
I am also mostly dominant, and I desire a mostly submissive woman. I think my preferences regarding dominance/submission (from both a purely sexual perspective and from other domestic perspectives) also plays a role in my body-type preference.
I eventually found my perfect match. My wife has an amazing outgoing personality that is compatible with mine (I am more introverted). She loves outdoor activities and athletics (she was a runner and a gymnast in high school and college). She is very intelligent and competent (she runs her own successful small business). But, sexually and domestically, she prefers to be mostly submissive. And, because of her petite frame, it is easy for me to dominate her in bed, and to put her over my lap for a good spanking when she has been naughty (we believe in strict family rules and strict discipline).
Having said that I prefer a dominant role (while she prefers a submissive role), we do switch things up occasionally. So, I love that, in spite of her petite frame, she is very physically fit. When she decides to dominate me sexually, she is strong enough (physically and emotionally) to exercise her authority! Likewise, if/when I am a "bad boy" (disobey a rule, behave disrespectfully, and/or say/do anything dishonest), she has no problem administering a leather strap across my ass. When it is uncomfortable sitting down for several days, I always wish that I would have had enough self-discipline to have avoided my wife's discipline! As stated previously, I am mostly dominant, but when I am required to submit to my wife (sexually and/or for punishment), her body type is PERFECT... she is petite enough that I must voluntarily/respectfully submit my much larger body for her to restrain me and to do with me as she pleases... but also, once I am restrained, she is strong enough to teach me a painful lesson when I deserve a good spanking/tanning!
I LOVE my wife's petite athletic frame (5' 1", 32A-28-30), ESPECIALLY her small/perky breasts/nipples, but they are definitely part of an amazing package-deal.