Shades of Grey

I love gray/grey*! Gray's in fact. Probably that stems from my great love of black and white. But I find it highly difficult to find just the right grey yarn to knit with. Whenever I buy grey yarn I am a bit disappointed by the shade once I get home or it arrives in the mail. Why is that?

One grey I have been coveting though is The Uncommon Thread's Lark

picture from theuncommonthread.co.uk

I might just have to try a bit harder to get some skeins.

What are your favorite grey's?

*Quite confusing this grey/gray distinction, but apparently it's just a matter of British vs. American English. Oh well.