Chrome, though I bought my first leica lens in black (the current summicron 2/50) and stayed with black (of course) when purchasing the 2/28 ASPH and (to be consistent) the 2/90 AA.
But then...I bought a chrome MP (next to my M6TTL chrome body) and fell in love..with the combination of the chrome MP with the limited 2/50 summicron "50 years" chrome edition. This combi looks so great, that now I have decided to buy a chrome 2/35 ASPH (and did this today!!!) (although I wonder was has gotten into me, since the difference between 28 summicron and 35 summicron is not really big..). But hey, the MP, chrome 35 and chrome 50 summicron make a beautyful set, don't they?
And thinking it over, I paid in total for the MP .72 chrome, 2/50 "50 years" and 2/35 ASPH in total EUR 4300 new..Not a bad deal, don't you think so?