I currently use Lightroom 2 but it only takes you so far, I've been told CS3 is better than CS4 so I'm not sure on which to get, any help at all would be great.

CS5.. it's the newest.

New doesn't always translate to the best. D:

In Adobe's world it does.

This

CS5 has some great new features for photographers especially.

For what I use photoshop for, I use CS2 mostly, and use CS3 for editing raw files (because it gives you more options). I don't use photoshop much, or know a lot about it nor am I talented with the thing, so ya! That's my two cents

CS5 has automated spot correction similar to GIMP.

For editing RAW files, you can't beat Lightroom 3.2. Big improvements from LR2 in the noise reduction capabilities especially.

As far as Photoshop, I suppose it would have to be CS5.

Canon Digital Photo Professional that comes with any Canon DSLR you purchase is also very useful and powerful. I haven't used Photoshop or LR for RAW editing but DPP is good enough for me and it supports even the newest cameras.