I don't really have a list, and prefer things as free as possible. There's no rules or law because some bikes are so differents that if something is wrong on a bike, it's good for an other.
For exemple : riser bar and negative stem. It's a contradiction. I admit. But, on a cannondale with headshok, it's a very good built for a better position on bike and for riding
Another exemple : SS built. I build my yeti FRO with only one gear, and the bike was very funny for rides. Respect of the BMX spirit of the frame. and SS is better for looking the geometry of the frame.
In Germany there's several categories for oldschool bikes : close to the catalog built, retromodern, singlespeed, free built… And I think it's cool.
But, for answering to the thread, I hate :
- when there's no respect of the geometry of the bike (wrong fork on wrong frame…)
- when there's V brake on canti frame
- “fashion built“ or "systematic built" (Grelo Fat Chance YoEddy with anodized parts)
It's subjective but :
I hate red ano parts on titanium bike