Best book showing off Clark and Lois' relationship?

I'm a sucker for romance and I love how Clark and Lois is one of the few couples that are permanent. Superman doesn't have the problem of Bats and Spidey where they have multiple love interests and you can't really please everyone, Superman just isn't the same without Lois. So what comic recommendations show the two off the best? It could be them first meeting and falling for each other or they could already be married, etc. Anything that shows off their dynamic.

Also, it doesn't have to be main plot, it could just be a subplot.