Best Game Engine For a NEW Game

Hi all,
I'm a noob and I want to start to build my own game.
After many many researches I personally think that the best engine for a game with the story like Nanny's Day could be a Sim's 2 !! That's because there would be much more freedom for the player to interact with each others and many more puzzle to solve !!
Unfortunately there is no Sim's 2 open source game engine...
as far as I know...
So , the question is : is there a game engine free/open that is similar to Sims 2 \ 3 ?
I'm also considering Irrlicht but the work to build up a game for that would be tremendous...
What do you think
I'm a noob and I want to start to build my own game.
After many many researches I personally think that the best engine for a game with the story like Nanny's Day could be a Sim's 2 !! That's because there would be much more freedom for the player to interact with each others and many more puzzle to solve !!
Unfortunately there is no Sim's 2 open source game engine...
![triste [img]images/icones/icon11.gif[/img]](./images/smilies/icon11.gif)
So , the question is : is there a game engine free/open that is similar to Sims 2 \ 3 ?
I'm also considering Irrlicht but the work to build up a game for that would be tremendous...
What do you think