(i don't own all content, so some of this might already exist. do let me know. but anyway. also pasting from older posts of mine, so this will be a mess.)
-space for more traits. and more of them, actually. more specific/personalised ones. for example, "film enthusiast", "tea lover", "coffee lover", "perfect pitch", "contemplative", "spiritual", "sceptical", "insomniac", "compassionate", "empathetic", "loveable", "cowardly", "destructive", "forgetful", "naive", "wishful".
these could all influence their actions and interactions/way they react to information or with objects, etc. even more than the ones we have now, some of which aren't really noticeable in-game.
-i would like to see things that pointed towards a disability or a chronic illness. i can imagine this would be difficult to implement in-game, so... even if i could, for example, place crutches/white canes by the door, or a heating pad/hearing aid by the bed, it would be a start. (stuff like casts, patches and bandages
could be added in CAS, though.)
-interactions that make more sense. for example, rejected romantic interactions should not be followed with the positive reaction (see: snuggle.)
-asking another Sim with high enough skills to repair something, or to cook a meal.
-"get to know" should stop appearing after all traits are discovered.
-fears, phobias.
-reading, daydreaming, listening to music, and counting sheep in bed. talking on the phone while holding a drink.
-reading and discussing books together. (can something like this be done with clubs?)
-curling up in bed when sad. different to "cry it out", as they are under the covers when they do that.
-this might be difficult, but: crying on another Sim's shoulder/in their arms.
-being able to touch foreheads with another Sim. like a tender/romantic interaction.
-brushing their lips together, different to the kiss we have now.
-sitting cross-legged. (can they even sit on the floor/grass/wherever?)
-slow dancing, and actually dancing with other Sims in a way that makes sense. usually they don't even look at each other, it's just the same as dancing on their own.
-walking while holding hands, and holding hands across a table.
-when Sims go on dates, stop others from interrupting a romantic conversation and creating an awkward mood for everyone involved...
-humming along to a song when they listen to the radio. (they can't do this now, can they?)
-more moods/moodlets. since we have "energised", it would be interesting to see "lazy" or "apathetic". and i have a terrible memory so there might be similar ones already, but... i'd like to have "overwhelmed", "sarcastic", "afraid", "proud" as a personality-related moodlet, "comforted", "confused" as related to feelings, "missing someone", "unsafe", "insecure", "self-conscious", "heartbroken", "hurt", and "distrustful".
have moods last longer, or be more difficult to change. some Sims *could* have more mood swings, though. but i think moods shift way too quickly now, changed by the smallest of influences.
-there could be "relieved" after "embarrassed". "amused" before "playful" kicks in.
-Sims who are Good could feel "sympathetic" after witnessing something embarrassing happening to somebody else, for example.
-a Romantic Sim could maybe get a "melancholic" or "yearning" moodlet. i think there is something similar already but IMHO doesn't make much sense for it to boost the "tense" mood. it could be the "sad" mood instead, and happen after he/she notices married/engaged Sims or displays of affection.
-"bring Sim here" when clicking on their portrait should have them appear in anything but night clothes. doesn't make sense to have the player change them before/let them go into a venue in pj pants... haha. related to this, when they wake up they could simply change out of their night clothes, like NPCs do.
-more musical instruments. for example, saxophone, bass, and drums. more radio stations. related interactions that could work with existent animations, for example: "ask Sim to play song".
-sheet music.
-more skin details/blemishes/imperfections. scars, burn marks, pockmarks, the like.
-injuries/wounds, in general, even if it's mild things like scraped knees or elbows, or cut/bruised lips, or black eyes after they get into fights (or for clumsy Sims).
-more illnesses, maybe a few base game ones. so mild stuff that could make Sims feel like sleeping for twice as long, having no appetite, etc.
-more body shapes. adjust heights. set handedness in CAS. have the dark skintones improved! more walking styles. (also, more animations for clumsy Sims!) being able to choose from "he" or "she", since we can now edit the gender-related aspects of our Sims.
-body hair for both genders. more curly hairstyles. headbands/hair-bows/turbans/hijabs. decorated braids.
-longer/looser tops and hoodies. looser jeans. flowing skirts and tops (like viscose) with different patterns. scarves, shawls and neckerchiefs.
-more big, long earrings. and, in general, the option to wear them on one ear only.
-a kettle! ;)
-laptops (were these added?) and Sims being able to browse the web, or research things, together.
-gift-giving, maybe a way to keep the flower Sims can receive as a romantic interaction too.
-something like "call to meal", but for tea and coffee. being able to mix more than one drink at the same time.
-football!
-winking. maybe the option to make one individual eye smaller/larger.
-sewing machines.
-bunk beds.
-floor fans, and small heaters.
-the option to have the game "pause" after each loading screen.
-the "jogging" action to be fixed, so that the Sim will stop when directed to.
finallly,
here are some fashion/accessories photos. also,
here.