I have been looking at the footage of Forza 3 and really like the look of the game. I have Forza 2 on my shelf and have played quite a lot of it but I am still no where near completion. The question is should I buy Forza 3 and play that or is it a waste of money when Forza 2 is there to be played.

I have been looking at the footage of Forza 3 and really like the look of the game. I have Forza 2 on my shelf and have played quite a lot of it but I am still no where near completion. The question is should I buy Forza 3 and play that or is it a waste of money when Forza 2 is there to be played.

Definitely! It's not like you're missing some key story elements.

I've played LOADS of forza 2 (about 40 hours DRIVEN alone_ and still havent finished it. It's a big game.

Simple answer. Yes. 

Forza 3 is faster, better looking, easier (depening on what you want). Has some great new features like rewind and better graphic design package. And whatever you design you can sell for in game credits.  

And then there are the achievements. They come thick and fast (see my review).

Might be better to finish F2 and then F3. By that time F3 should be a little cheaper. Of course, that would depend on how fast you finish F2.

I finished Forza 2 pretty fast myself, but I think you should definitely get the new one...it's a big step up and you'll feel weird playing Forza 2 when you know you could be playing 3.

" I've played LOADS of forza 2 (about 40 hours DRIVEN alone_ and still havent finished it. It's a big game. "

I'm not going to wait to finish Forza 2 personally, nor will I ever beat it.  I am so tired of messing up that one turn and putting the car into a wall after 10 minutes of racing or messing up a turn and getting passed on the really hard races.  The rewind feature may make the game a bit easier, but I'm looking forward to it immensely.

Yes, you should get Forza 3.
 
Twice. It's just that good.

Forza 3 is the way to go.  Oh and by the way, you probably wont finish Forza 3, not with all the stuff there is to do and play around with.

No! There's a HUGE spoiler at the end of Forza 2 that, if you don't see, you really can't appreciated Forza 3's story.