With my first partner, I orgasmed from vaginal intercourse pretty much every time. With my current partner, I almost always have to stimulate my clit in order to come... but I also have more multiple orgasms that way.

I do wish I could orgasm vaginally with my current partner more often, but I honestly think that the size/shape of his penis (pretty big, sticks pretty much straight out with no curve, compared with my ex, who had an average-sized penis with an upward, g-spot-hitting curve) doesn't help me there :P