Together since university years almost 2 decades now, married 13+ years. Anyone expecting the electric buzz of the first year and the pink clouds is simply delusional, that is not how things work, things inherently evolve. Two people, two bodies, two minds - as they spend time together they get more accustomed to each others' individual traits, in an ideal world, they are getting better at being a unit, like two pieces of puzzle being chiseled more and more to complete each other. There will be ups and lows (and i don't necessarily mean something dramatic that needs to be forgiven, but stuff like - momentary dip in finances, or maybe reduced quality time as the couple has children...)
Having said that:
Our relationship with my wife is like the food I'd pick if I could only have one meal for the rest of my life. It's something I could never get bored of, there is always immense pleasure in it, it is comfortable because I know it very well, but I still love every bit of it. It balances out - I love going on dates with her still, I love our conversations and dumb jokes, I love it when we solve a problem, each of us bringing our own strengths in, love seeing the world with her, holding her hand, or looking at each other with an awkward face when one of our children does something silly, it is a comforting constant in my life.. It's peace, basically. And then there's intimacy, now that's when we still have the sparks. We are not blind to each others' flaws, we don't see each other through rose-tinted glasses, but it does make our heart pound harder as we pleasure each other. It is not boring, it is something I actively look forward to.. Combining the excitement of intimacy with the peace of the well-oiled machine that is our lives, I think it makes for a healthy combination. It works for us.