I put styles in parentheses because it might just be one thing or a whole look.
Me, I dislike leather trenchcoats. Sorry, they look pretentious. Like you’re trying to hard to say “I’m a mean scary villain guy”.
I do like cobblecloth shirts though.
I’m not big on shrugs and I hate a mid-calf skirt unless it’s worn with boots.
I think men should wear hats only for practical purposes (such as warmth or blocking sun). Any hat worn just for fashion reasons (like a beret or fedora or whatever) just look horrible to me and make me think the wearer is an attention manwhore.
I can’t stand low rise jeans. And I especially hate them on little kids. There is a girl in my son’s preschool class who wears only low rise jeans and her little crack is showing all day long.
My 25 year old niece had a pair on at Christmas and her crack was showing half the day.
I had my son sneak behind her with a candy cane to stick back there after we had seen it for the 10th time.
I love jeans worn with a long-sleeved white shirt, on men or women. I like the shirts Charlie wears on Two and a Half Men but I don’t like it when he wears shoes and socks with shorts – the socks are too high. But that’s just me – shorts call for sandals, no socks. I like Rose’s sweaters and those short skirts she wears. Don’t like Alan’s polo shirts.
I don’t like capri pants or whatever they call women’s pants that are mid-calf length.
I don’t like cap sleeves or short puffy sleeves on women’s shirts. Don’t like three-quarter sleeves either, and I’m tired of tightly fitted blouses that are too short to be tucked in.
I love camp shirts, especially silk or rayon.
Love lightly-fitted suede jackets that hang just past the waistline.
Love long-sleeved tee shirts.
Hate sweatshirts with kittens, puppies, “I love grandma”, etc. Hate any knit shirt with a band at the bottom.
I dislike a lot of the things that have already been mentioned but I’d add animal print clothing, lots of tattoos, cutesy things on adults that belong on little kids, and those popular blouses that make me look like a pregnant teenage peasant girl. White buck shoes on men crack me up, as does anything approaching the zoot suit look. And then of course there’s the sock/shoe/sandal combo rules violations.
Men look best to me when they’re dressed in jeans, flannel shirts and tee shirts unless they can carry off a suit comfortably. I love suede jackets but not leather (on me) and I love my men’s 501 jeans way more than my dressier ones. After years (decades?) of dressing like a hippie I now avoid fluttery layers, clothing with more than 3 colors in it and my tiedyes never leave the house. If someone wants to wear tiedyes they shouldn’t be those cheap imitation ones - find a real deadhead who makes them or don’t wear them at all. I like my Ugg boots even if they look retarded as soon as you get 20 miles away from surfing areas. I love lots of my more professional and dressier clothes too but I have no use for them anymore and I’ve been slowly giving them all away. I was overweight for years and now that I’m not I don’t wear oversized or baggy clothing no matter how comfortable or in style it is.
Holiday sweaters should be illegal as should cheap black concert tshirts that fall apart and stretch out after one washing. If you’re more than 20 pounds overweight spandex is not your friend unless it’s in the form of workout gear.
That made my day! 
I hate pleated pants on anyone!
I dislike/will not wear the following (25yo black female from MN):
Shoulder pads
Checkered Vans
Sweatshirts with no hood (although was forced to at Boot Camp and in a bind will wear my boot camp-issue sweatshirt) I think sweatshirts only look acceptable on men, on the way to/from the gym…and I dislike turtlenecks worn under sweatshirts.
Berets
Door-knocker earrings - unless you’re Queen Latifah from 1993
I do enjoy wearing:
Hoodies
Scrub pants
New socks (if I had it my way, I would wear a pair once and discard. Same with Polar Fleece, I’d wear it through about three washes then discard.)
Driver ivy caps (sorry Rand Rover, but it’s one of the few caps that I don’t feel like a total douche in)
I think that’s about it…
I hate cowboy hats on just about anyone. Actually I hate “Western-wear” in general. I think it’s hopelessly tacky; I don’t care who you are.
I think every woman looks fabulous in knee-high boots, particularly with a good heel.
I hate pale, washed-out denim. Guys are particularly bad about wearing it; it’s so eighties. Buy new jeans!
I’m not a fan of leather jackets in general, particularly the James Dean/bike-rider variety.
And Oxford shirts with short sleeves are an abomination. They should be banned.
I hate pleated pants, mainly because they’re a pain in the ass to iron. I do like loose slacks and long shirts of any kind, including sweaters, tee-shirts, long sleeved shirts, and tank tops. I’m talking the kind that are almost dress/short-skirt length.
I really liked those long ruffled peasant-girl skirts, even though they made me look like a Christmas tree. Unfortunately, they seem to be out of style again. 
I hate high heels (except for boots) and I love flats. I’ll wear low heels and chunky heels, but those spindly heels have got to go.
I absolutely cannot stand the 1980’s style look- you know, ridiculously long shirt with a belt and some spandex.
Other styles I hate:
*another vote for low cut jeans
*baggy, hangs below your ass jeans
*grunge/goth
*another vote for cutesy t’s, sweaters etc
*mini skirts and really low cut tops on anyone over the age of 35
*ridiculously short pleated skirts, especially when paired with UGGs
I love:
*stilettos
*boots
*guys in dress shirts
*just past the knee skirts and dresses
I hate:
Hip huggers, on almost anybody. HHs are all right on very thin people. Muffin tops do not look good on anyone.
Sagging. One of these days I’m gonna go postal and start giving wedgies.
Baseball caps with the bill turned any way but frontwards.
The whole rhinestone cowboy look. Cowboys/ranch hands/farm hands wear work clothes that do not need to be dry cleaned or hand washed.
Bolo ties. Very few people can pull off wearing a bolo tie.
Sexy fashions for gradeschool girls. Playing dressup as a princess can be cute. Playing dressup as a whore is NOT.
I think that most shrugs just look wrong.
I love:
Cowboy hats on most people, even though most people who wear them don’t really need them. Similarly, fedoras look good on most people (male and female). Most guys look better if they wear a (reasonable) hat.
Kilts. Guys, these increase your sexiness by about 1000%. Really. Even if you have a belly, you’ll look yummy in a kilt.
Shawls and ruanas and cloaks, especially when held together with a striking pin.
I love knee-high boots, but they do not love me. Even when I was slender and well proportioned, my calves were well-defined, and had a definite curve. I am also quite short, just a whisper over five feet. Knee-high boots look much better on women who have legs that are longer and more up and down.
Ever see one that wasn’t black? I have a 70s vintage chocolate brown one I quite like. I wear it with a newsboy cap.
Rand Rover and Karyn, II’m afraid I can’t consider either of your opinions on fedoras and white bucks “humble.” (I wear both, at intervals.) There aren’t enough guys that wear either to get in anyone’s face - not 1% of the backwards-ball-cap or hip-hugger crowd - so I can only assume you have some sort of issues with someone you’ve met who wore these things. And I can’t be responsible for that.
In my neighborhood I see a lot of baseball caps with the stickers still on the brim, which is always flat as a board. They look about as intelligent as someone who forgets to take the stickers off their clothes
You’re very mistaken. They look stupid when you’re within 20 miles of surfing areas. They only begin to look like an intelligent choice in footwear when you’re within 20 miles of snow.
Does that mean it’s OK to wear a fedora if it’s cold and if, as in my case, one is bald, or do I have to wear a ball cap or a woolly cap?
love-dress tops with capris.
hate-any top with appliques or holiday items
I always liked those, too, but I found that they’re way better on tall women. I am petite, and I always got lost in them.
I like zoot suits! There’s a place out in California that sells all sorts of different styles and someday I’m gonna get me one. Or two.
I wear short-sleeved oxfords in the summer because they keep me cool and I like the way I look in them. But none of that polyester blend crap - 100% cotton for me, thank you!
My absolute favorite style, however, is the turn-of-the-century sack suit. There’s a guy up in Canada who makes vintage-style clothing from the 18th to the 20th centuries and he’s gonna get a HUGE chunk of my money if I ever get that amount of disposable income. Detachable collars, spats, an’ either a derby or a homburg. The works.
So many people here wear them that at least we look stupid in a crowd. Besides, they were first popularized by surfers in Australia. From here:
They don’t hold up very well in rain or snow.