I've had two made by Dan Prendergast in the UK http://www.prendergastknives.com/ and they are both wonderful. Both carbon mono-steel but he does amazing san mai as well.
I think Bloodroot blades http://www.bloodrootblades.com/ has a multi year waiting list for customs but they do a monthly mailing list sale which has gorgeous stuff.
I love Joe Schrum's knives from Halcyon Forge and would love to get one http://www.halcyonforge.com/.
Top of the list though if I was going to go all out would be one from Ian Haburn. http://www.haburnknives.com/ his stuff is insanely beautiful.