They used to say that you should choose a partner who's the opposite of your temperament. From my experiences I must say they're right. If you are an introvert personality, then you should choose a partner who's extrovert.

I'm a quiet type of guy myself and I had a shy and quiet girlfriend. We were hanging out and stuff but never knew what the other wanted. Two quiet personalities doesn't go along well. Neither party can speak out and it ruins the relationship.
Communication is very important in a relationship.
I never could discuss intimate things with my gf, as both of us were shy and this evetually led to a breakup.

But in fact I like quiet girls, because they don't go with the flow of today's so popular "culture". Deep in my heart, I would prefer a shy girl, like my ex girlfriend.
And of course... I don't think that a loud, extrovert girl would be interested in me.
So it's pretty hard. Maybe that's why I don't have a girfriend for 3 years now...