I am currently addicted to Harvest Moon Animal Parade for Wii. It has some features in common with the sims 3 such as a developing community where members get married and have children. However, it also has its own unique features such as owning pets you can train, participating in festivals, and more farming options. I would love to see a talented simmer build Harmonica Town from this game in CAW. I know one simmer did Mineral Town from the gameboy version and play that town quite often.
I can't decide which is my favorite game (TS3 or Harvest Moon). I would love to see some Harvest Moon elements in a future TS3 EP (animals, mining, more story-oriented quests, festivals and holidays). I wish both games had more interactions for babies and toddlers as they are my favorite life stages.
My favorite TS3 EP so far is ambitions. Love it. I think my favorite all-time EPs would have to be the pets or vacation-themed ones. I was dissapointed WA didn't have more tourist features even though I love the puzzles. One day, I built some tourist lots in some of my destinations such as a family park in France. I think my least favorite EP was Superstar for TS1. The only things I really liked about that EP were the babysitter and the dive tank.
Basically if I could do anything to improve sims or harvest moon, it would be more children and pet themed objects, options, and interactions.
My favorite games when I was younger (adolesence) were catz 5, dogz 5, and babyz (by P.F. magic). Unfortunately, I had to stop playing them because they wouldn't run well on later versions of windows. All the newer games in this series are more mini games than virtual life so I don't play them.
Two really well-done virtual life games are My Baby First Steps and Nintendogs for the Nintendo DS. My Baby doesn't have much replay-ability once you do it once though.