Hmmm...that's a tough one. I can have all three types. Certainly clitoral is easiest for me to achieve during vaginal sex. Postion really doesn't matter.
My favorite type of orgasm is the "G Spot" orgasm. But that doesn't come as easily...no pun intended
I really have a hard time getting off via tounge action. It literally takes almost 1/2 hour to an hour. I feel too bad to ask my boy for it...although he loves it and says he never minds to spend the time.
These orgasms are cherished simply because of all the time and effort. Plus they are so few and far between.