I have the Sims 3 on steam and it doesn't require Origin. Of course, it's been a few months since I was able to play it last, but I would launch straight from the desktop.

bit of a late answer. But as far as i know that's not the case. However, later expansions such as generations, supernatural, etc, does require Origin. Not sure at which point they came up with it, but if i'm not mistaken that was with generations. Anyway, if you want everything which came out then better go for the retail version.

Does anyone know if the Sims 3 version here requires Origin or not?