I think the white PS3 they showed back in 2006 looked amazing. I've always been quite disappointed in Sony for not offering users more choice when it comes to shell configurations. Seems like a no brainer for Sony to offer these, but traditionally they have always been very slow to offer them/bring them to market. I hope PS4 has this customisable shells as standard, but who knows what that console will be like (might even be small/portable like an iPhone, but that you can still plug into to your HD TV). In which case it's kinda so small it doesn't really matter as much (it's not a display piece in your living room anymore).
All I have is black. Two from when I bought the system and one from the LBP + DS3 bundle. I'll have another black one when I pick up the Uncharted 3 PS3 bundle next month. Wouldn't mind a red or blue one just to be different, but I don't really need any more yet.