[Throttle]

I can heartily recommend Armageddon and Shadows of Isildur. Both are top-notch roleplaying muds, arguably the best two out there, and both have reasonable playerbases as well as numerous competent staff members.

Armageddon is a little more PvP-orientated, although it's not what the game is about. There's just a lot more conflict. I found SoI's social scenery to be more ample, its world better written, and its code vastly superior. It has one disadvantage that is its setting - it's Tolkien's Middle-Earth, and since they have to adhere to the canonical story, your role can be somewhat limited as you cannot do anything that deviates from what Tolkien wrote in his works. That doesn't mean that you can't do anything that isn't written in the Lord of the Rings, but everything large-scale and world-affecting is going to be done in accordance with the written works. Armageddon is praised for its brutally harsh environment where survival is a real challenge, where oppression is an every-day occurance and where you can experience plenty of their motto: murder, corruption and betrayal.

Edit: I missed the "no pk" part in the OP. I don't think you'll find a real roleplaying mud that has no playerkilling because that's part of what makes for a realistic game. I guess an RPI-mud isn't for you. I still think you should give it a shot, though.