My DH had a double bed for about a year before we married/lived together. Before, we were both in twin beds. He started getting used to his bigger bed and would hog it when we started sleeping together on it.
We have a queen bed now and it's much better. Now we just worry about the cat hogging the bed.
I have a twin that I bought right out of college, but the second I get out of NYC and have regular-sized living space, I'm upgrading to a queen! Why wouldn't a full-sized mattress be good?
Jodi, anything would be good. It just depends on the space and money. Just an fyi though, the most common sizes around here are Twin, Queen and King. We have Full sizes too, just not as easily found.
I have a twin. I have always slept in a twin, even when married(neither one of us could stand sleeping with another person), and have a terrible time trying to sleep in a full or queen size hotel bed. Have to pack pillows around me to make the space smaller. Besides a twin makes more space available in the bedroom.