I adore mods, but have used them almost exclusively in The Sims series. I can not play The Sims series games without mods and Custom Content. In The Sims 4, I actually got bold and learned some basics of modding and Custom Content and I have made a couple of small (aesthetic) mods and brought a ton of CC (some I release publicly, some I keep to myself - especially the ones that are models from other games).
Mods add much needed depth, especially in a game like The Sims 4 which is pretty shallow to begin with. I have an LGBT mod that parses out a percentage of the population to be LGBT by each and it's great for variety in the game. It also automatically sets sims you play so you never know how a sim baby you have will grow up! I also like the added Likes and Dislikes mods, where I now have likes and dislikes for weather and seasons. I have mods for added traits and mods for more realistic pregnancy and romance, etc.,etc. I have so many mods it's hard to know where to start. They're all a necessity to me!
My favorite, though, is the playable oboe that JaneSimsten did!!! <3
(my happy Simself playing my favorite instrument!)
JaneSimsten is the first modder I have ever found that can make new instruments that are fully implemented into every game system and have all of the depth of the EA made instruments. When she was willing to make woodwind instruments I was so happy!
But also, as a CC creator myself, I love the freedom to just put whatever I want in the game. I have toys of my favorite Pokemon, toys of G1 and G3 MLP, I have decorative versions of almost every instrument in the wind ensemble, I have models of the shawm and aulos that I created. I have personal paintings/wall decor. I also have created tons of Christmas CC! I adore the freedom of being a CC creator!!
It makes me wish Animal Crossing had a PC edition. The custom content possibilities would make Animal Crossing amazing.