Well, different shapes for different things.
Oral and anal: Short and thin, obvious reasons
Vaginal: THICK, and not too long. I had my cervixed bruised once by a long, careless lover, and the pain and spotting afterwards sort of let some of the fun out of the experience.
I have learned to really appreciate thick cocks. I have always loved the sensation of my vagina stretching when I am first penatrated by a partner, and when my partner is thick, and pushes into me just right... ohhhhyesssss... BABY!!!!

post-orgasmically (thanks to a toy, DAMMIT)

Wanda

__________________
"I wondered, am I a lesbian, am I straight, or bisexual? Then I realized that I am just a slut.
So where's MY parade?"

---Margaret Cho