regfee, unless the letters are are of some significance. I haven't run a full scan, but I'd expect there are still a few hundred, if not thousand, LLL.cc domains left in the "wild."
I was actually very tempted to reg PTO.cc when it was available--also stands for "Paid Time Off". Of the one's listed above, I agree with Yandig that this one is the best.
I currently have two lll.cc's in my portfolio, one of which (thd.cc) was regged during the brief hubbub surrounding the launch of TotalHD technology.