1) A guy who is so nice to every girl he knows that before he knows it, everyone is past the "Friend" threshold and thus impossible to date due to the "I don't want to mess up what we have" argument.

2) A dildo.
by MoonKnight March 29, 2003
every girl's best friend is someone who is there for you inspite of the negative things you do and say to them. Someone who will laugh and cry with you in the mist of their problems. Someone who will give you their last even if they need it.
If you are angry with your friend and use against them information that only you know and you still remain friends, that's a best friend.
by Angela February 26, 2004
1. A brain
2. Gay dudes (trust me, you'll find out why)
3. Diamonds
4. A Camaro, especially a black or royal blue one
Not every girl's best friend is a diamond. Some like flowers and ohters like fart jokes.
by RatchetBoo May 9, 2003