BMW hands down, but I do think Lexus builds a pretty high quality product, i mean toyota does. The only japanese cars I like right now that I would consider would be an infinity g35 or a nissan 350Z. The lexus has always seemed a little big and not quite the same level of performance as the BMW but they and all of the competition for the 3 series is getting tighter and tighter. But your only going to get people voting for BMW.
As far as being pissed if I find BMW parts in a mini, or Land rover i don't give a shit because I know that they should be quality parts since they are made by BMW. Also remember BMW and all car cos will do joint ventures on research and share parts, they do it on engines/transmisions etc.