Shoutbox

That person obviously has no idea what hes talking about. I have all of the expansions installed (which are released every 6 months) and it adds a ton of stuff to my game which i would miss having if i was just left with the original game again.

University - Lets your sims go to university and get a degree and then once they've done that they have some extra benefits.

Nightlife - lets your sims go clubbing. My least favorite although it does give your sims the ability to drive.

Open for business - lets your sims start their own business on their own lot or they could buy a community lot and do it on there. They can hire and fire staff and their businesses can go up and down levels giving them benefits which you choose when they do. They can also get talent badges (aswell as the skill points).

Pets - They can have birds, cats, dogs, fish and more (can't remember them all). You can customize your pets completely and then the dogs and cats can get jojbs and learn tricks and all that.

Seasons - You can have spring, summer, autumn and winter. Each season lasts 5 days and has its own effects on your lot with the trees and things. I like it how the snow covers everything not covered by something else so it falls realistically.  It also allows you to do fishing and gardening and do lots of new things really. My favorite so far.