I'm not a purist - I don't mind using adjustables.
I can confirm that stanley locking adjustable is a great tool. Ever try to put a quick connect fitting onto the end of a piece of hose? Just lock one side into the stanley and turn the fitting on with a wrench - it's great - and for $12 it can't be beat. Here's the link to the US listing on Amazon:
http://www.amazon.com/dp/B00009OYGZ/?tag=atomicindus08-20
I also really like another pair of stanleys - I think they are called maxgrip adjustables. I have a 6 inch pair and a 12 inch pair and they have a black oxide finish and a nice rubber covered handle.
I have a bunch of older ones - a few 12 inchers - challenger, diamond and crescent, which are all great. My all time favorite is a Fuller 12 inch, with a smooth as butter action.
I also have several other pairs including some Craftsmen, which I would say are so, so, and a couple of china ones that need to go into the donation box . One of my most used is a Kobalt 6 inch I have in my small belt toolkit - nicely finish and works well. .
I'm always trying out new stuff and even though I got a winner with that locking adjustable above, I've gotten some losers too:
I tried the Bostitch ratcheting adjustables they started selling a couple years ago. They do work as advertised if you have the perfect access to the bolt, perfect range of motion and the bolt surface has no flaws; however I rarely find a bolt with that combination of perfect access. And even though the tool handle is big and beefy, the ratcheting jaw compromises the strength such that they aren't all that good in conventional mode.
I also had somebody give me something called a "bionic wrench" that has five clamping jaws that grab a bolt when you close the pliers type handle - I can clearly imagine the infomercial that must have sold the thing - it's near total junk.
Somebody earlier mentioned the Knipex pliers wrench. I bought a pair based on the recommendations here and I must admit disappointment at first. But then I learned how to use them - you have to open the handle, then open the jaws, then close the jaws over the bolt with the handle still open - which properly adjusts the tool, then it's ready for use. It's frustrating to try and adjust the tool independent of the bolt After I figured this out, I was able to realize the benefit of the tool, and use it quite often.