The original you posted is the best - don't listen to everyone saying it's too dark. The most important thing is it looks natural. Raise the exposure too much on the face and it looks unnatural. Colors and stuff look good.
If the original shot was taken in a different environment with that amount of light on the face it would still be a bit dark, but it would be better. Don't get me wrong, I love shadow in portraits. You can use them really effectively with a bit of practice and luck. Here's one of mine that's actually way darker in the shadow areas than the original image.
That was shot with environmental light only in a not entirely different situation (large indoor space with a load of stuff going on behind, and actually quite a lot of strong light that I couldn't use - it's not the best one of the set but those are being published shortly so I don't want to put them on the internet). It's pretty dark in places, but it works, largely because the subject is isolated and there aren't any competing elements in the image.
The reason the face looks too dark in TexChappy's shot is that the light isn't managed as well as it could be. There's a really strong backlight that 1) draws your eye away from the subject and 2) makes you think "Why didn't he put him somewhere brighter, if there was all that sun available?" Also, what light there is is very flat. There's no pop even to the brighter part of the face, probably, again, down to the backlight. These things are all useful to think about when you're shooting portraits - which is one of the hardest things in photography to do well, the easiest to do badly and also one of the easiest things to improve rapidly, if you ask me.
The camera is certainly doing its job and from what I can see here is well up to the job of taking nice, sharp pictures with lovely tones. But taking good pictures has absolutely nothing to do with what camera you're using, how good it is, whether it uses film or digital or anything else. It has to do with the way you look at things and how you work with/make use of your environment.
Texchappy, don't think in terms of being better with film or worse with digital. Just treat digital like film ie view your Raw file as a digital equivalent of a negative that you can work with to make the print you want, but try to get the image as close to perfect as you can in camera in the first place. Most of all enjoy shooting and do it a lot. A good digital camera is great for that: it allows you to shoot as many "rolls" as you like and to experiment to your heart's content with no film costs or developing time. That means you can experiment and play around with ideas, which will really benefit your work in the long run.