My fixie is a definite spare parts build. Conversion frame, suicide fixed, cheap cranks, mismatched spare wheels. But it has a nice bottom bracket and is well maintained so it rides well enough I think. My ss cross bike has nicer parts by far but is by no means fancy. Nicer wheels (depending what's on it) cranks, etc.

I think because I race the cross bike I can justify nicer parts for it for some reason, not that I have any illusions about it making me much faster. It's totally logical, but I think that factors into my reasoning. I also like having a bike I can lock up and not cry over if it's stolen.