Ah, that's something that I forgot to mention!
What difficulty do you currently play on? If you're playing at a low-level difficulty and are finding yourself bored by how easy the game is, experiment with increasing it one level at a time. Personally, I am currently playing on Expert, but that's because my character is a very leveled, uses weapons with high damage ratings, and wears armor that exceeds the armor cap. I was becoming bored with how easy it was, and gradually increased it until I found a nice balance again, and am now enjoying it once more.
Another thing that you should try doing (if you haven't already), is exploring everything either by foot, or by horse. If you're the type of play that will fast-travel from place to place as much as possible, it's easy to find yourself becoming bored with the game, especially once the main quests have been finished, as you're not doing a whole lot of exploring and encountering a lot of enemies. When you travel by foot, or by horse (not by carriage, either), you're more likely to find new places to explore, be it caves, dungeons, Dwemer ruins (my personal favorite), etc. and thus, new enemies to battle. This also plays a large factor into playing a character with seriousness, and thus, playing the game with seriousness and realism, as in reality, fast-traveling just isn't possible; you'd have to travel by foot, or by horse.
All of these things are ways to find new senses of enjoyment from the game, and will definitely help you to make your next playthrough a more enjoyable a lengthy one, which is what Bethesda intended when they made the game as vast and explorable as it is. You just have to get it in your head that you're going to dedicate the time and effort into playing the game as if you were really inside of it, and it will instantly become more enjoyable, as you'll find yourself doing things you never did before, in ways that you never did before, and you'll find that you lose yourself in the game much more, which is 90% of the fun for me!
