What is the best stretching exercise i can do?

Marin Y.
Some of my favorite stretches to do are:
Touching my toes
Tree pose
Cat/cow pose
Reaching behind my back(as far as you can go)
And finally rotating my neck from side to side

Herbert G.
i like to flail my arms around, if you know what i mean. after doing this my shoulders feel very relaxed and free. i also like to stretch out my spine by bending my self "in half". my back feels great after this.

Owen T.
If you need back stretching do cat stretch/kid pose and you can also do the seal stretch. Another great one is stretching your wrists. And my favorite are straddle and Pike.