What I would like to see in the game:
1. Aliens take females as well and knock them up. Perhaps even the Alien staying and having a life with the sim should the sim be single or if married work his arse off to get said sim.
2. Would like to see my Teens be young adults even if they do not go to college, lets face it you do not simply go to adult from Teen there is a young adult stage.
3. The ability as an adult to go to college should they wish. Some times we regret our choices we have made
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4. To see adults life span last longer and be more of age like the elder and do not turn old till they reach 60. Then be more random when they die. I do like the genie because you can do the live long life and I had a sim live to 110.
5. Once a sim dies they remember the loved one this way my graveyards are used for more than just seeing ghosts. I made a custom graveyard for my towns and all the dead are there once they die. Including the Goth family and the family in the graveyard in downtown that has showed up and I do not know which expansion did that since I do not play Downtown to much and I know it was not there before pets that I remember.
6. I would love to see EA fix it so when your sim is pregnant she can use any clothing she wishes rather than the awful maternity clothing they currently use. I have never been able to get the hacks for this to work without conflicting with the other things like take my picture, play functions, give gift, ect being broken.
7. Better Jobs and update of the old ones. Also a better and updated majors in college to choice from. I would also like to see you be able to work from home in some jobs or have the option to do it half the time rather than have to take a day off all the time. One other thing, when you go on vacation you actually use the vacation time you have.
8. Better and or more hobbies and even see cars break down and you be able to fix them via tinkering.
Now I saw in the start of this post where someone was talking about aging babies, you can do this in debug mode by spawning the tombstone of L & D to a sim in his/her home. One of the options on the tombstone allows you to speed up any age. It also allows you to get your sim pregnant and even speed up that to.