Tricky one, knowing full well the Allegro and Pacer are crap i do have to admit i actually quite like them for being quirky and sort of charming and at least they don't look like anything else.
Balocco, agree the Arna is without a doubt the worst car ever to sport an Alfa-badge and the Minor/Ital is best left forgotten.
Could have named some more recent offerings from both Porsche and Ferrari for being hideous to look at in my opinion, but they might actually be great to drive and therefor unsuitable for this thread.
Was thinking of putting in some nondescript models out of the ranges Kia, Daewoo or Hyundai have to offer for being boring faceless and uninteresting to drive or look at, but at least they're not offensive and serve a purpose for being the own-brand of the automotive world for those not interested in cars besides mere transport.
So here it is, a Lancia Lybra, it looks awkward from most angles, dull in profile, and is unworthy of wearing the proud Lancia badge.
The most painful thing about it is not just looking wrong and almost nondescript apart from those bug-eyed headlamps, but it seems they've actually tried to make an effort somewhere halfway during the design process.
At least those Korean brands didn't try to make it interesting and the Allegro and Pacer took their wackiness to extremes.
Buying this suggest some brand-conciousness and trying to be "interesting" but not really getting it.