As a long-time WFRP player and GM (as long as the game has been in print in fact) I would say that if you're looking for a dark, gothic, fantasy game, then WFRP is your best bet. The rules are not without their faults (find me a game that is without fault!) but they work none-the-less.
Unlike Dagger75, I think the
gritty and nasty is the backbone of WFRP, indeed, the back cover states
A Grim World of Perilous Adventure. ruemere has a better understanding of the game though. I agree that the individual races are not balanced with each other, but why should they be? However, in my current (yes I'm still running the original WFRP), all of the PCs are humans (they are all from the same village).
With regard to
The Enemy Within, it is the greatest campaign ever written for a roleplaying game. Unfortunately, trying to get hold of the later installments (especially
Empire in Flames, the final part) is almost impossible
Finally, WFRP v2... I've playtested this and, while I cannot comment on what's in it (NDAs and all that), I think you'll be OK with the original rules for a while yet...