I totally understand about mismatched furniture and having LOTS of it(my living room!). In a pinch, slipcovers can help coordinate furniture pieces. As for the extra stuff your husband brings in...you could make it 'dissapear' while he's at work or with friends playing poker, or, you could explain to him that all that extra furniture is costing you both in space and upkeep - if you have too much stuff then you can't find/utlize the things you actually use. You could also suggest that he chooses to part with one piece of furniture that he likes least before bringing another piece in.
Thanks for the suggestions