Married 19 years, a house, six kids, three cats, etc. It's still usually great.
For those who are looking: if you can't see yourself in 20-30 years waking up with that person's mother or father, (cause we guys turn into variations of dad, and girls into their mothers) move on. If you have a best friend of the opposite sex, don't be afraid to advance the relationship.
After the twice or three times daily sex ends, you'll want someone you can talk to about everything.
Good luck