Boxers. I've met some (either really excellent show quality, or Boxers who are so far from being up to breed standard they could be called Pit Bulls) who are stunning. But, many more who are bug-bloodshot-eyed, have twisted faces, crusty noses, weird jaws, scream bloody murder, have snot/dirt constantly flying from them. Paired with gangly legs that are hurled at your chest 99% of the time. I know they are one of the breeds that is supposed to look silly, but I couldn't see myself living with that. I used to want one! But after spending time with thousands, the vast majority terribly bred, I am past that phase.
This is why I don't think I'd really like a boxer from a breeder. And the health issues, ugh. I think boxers are flipping ADORABLE but I don't do slobber or snorting. Gavroche is very un-boxer-like (and really I still think he's at least mixed with American Bulldog). He doesn't snore or snort, he doesn't drool. But he does have one seriously ****ed up bite.
Anyway, I don't think there's any breeds as a whole that make me want to gouge my eyes out, but there are traits I don't like and breeds that tend to just be "meh" at best.
I'm not a fan of the way labs look, with some exceptions. Sometimes I do find a very nice lab that I'd actually love to own.
I don't like English bulldogs. And probably at least 90% of EB breeders. It seems like everyone and their mother are breeding EBs to make a quick buck. They have wayyyyy undershot bites, are stinky and snorty and stinky and drooly and stinky and FAT and stinky. There is ONE bulldog at work that I like. He's clean, not fat, and not crazy wrinkly and crap.
I'm not a fan of most GSDs, though there are some well-bred ones that I do like.
I don't care for yorkies at all, and actually most small dogs I'm not a fan of. I don't like toy or mini poodles, though I LOVE the looks of the standard poodle (but not in show coat). I don't like dogs that have so much hair you can't tell that it has a head, let alone eyes. I don't like most brachycephalic breeds, though some are worse than others - such as pugs and pekes. I don't like most chihuahuas, though there are some cute ones. i don't like dogs that look like their eyes are going to pop out of you squeeze them a but too hard.
I prefer smooth or wiry coats - I'm not a fan of most long haired dogs, though there are exceptions.
I honestly wasn't a fan of the look of collies - especially smooth collies - but it kind of grew on me lol. I think smoothies in particular are gorgeous now, but it was an acquired taste. I don't like the look of border collies, except for the smoothies. That's that hair thing again.
I like cresteds, but other hairless dogs don't appeal to me. Though I LOVE hairless cats! I didn't used to like cresteds, either, but they also grew on me, and I would own one now.
I don't like cropped ears except for in dobes and min pins. They look funny to me when they're uncropped.
Not a fan of the looks of pembrokes, but I love cardigans (and it really, REALLY annoys me when someone says "welsh corgi" and doesn't specify if it's a cardigan or a pembroke...the receptionist at work wants a corgi and I asked her what kind and she says "Welsh" ugh, NO, tell me WHAT KIND).
I didn't used to like doxies, but they've kind of grown on me too. I don't like the long hair doxies much, though. And I don't like the black and tan much.