I was showing a $1M+ home about 10 years ago - BRAND NEW construction and fell (in a dress!) after mis-stepping into a 'sunken' drop zone...and had a catastrophic injury from it. 4401 Belknap Road - I'll never forget the address!!

Yes, I dropped into the drop zone! I will never understand why that little half-step would ever be a design need - or why it ever has been a 'thing either!

Maybe it didn't occur nation-wide but in California there was a period of time in home building where the "conversation pit" was a "cool" feature in residential building.  I don't know if it was a trend or even significant enough of a feature but it certainly is a space hog where square footage is wasted.  Thankfully, while it can be seen in some homes it wasn't widely available in Pasadena although you can see its impact on some unfortunate remodels much after the "trend" moved on/died.  

Krista funny but the gate has been opened and the horses ran away.... too late, Trends Sell everything, I remember when I was growing up there were the Avocado Colored appliances and the Lemon Yellows....well you know....Endre

I have nearly fallen many times in those sunken living rooms.

Cookie cutter construction. Whatever happened to diversity in architecture? These new developments all have houses that look the same

Built-in bars in living rooms... but I think those have gone away. Thankfully, popcorn ceilings don't seem to be common in newer construction.

Two things I get rid of in my homes, Carpeting and Drop Ceilings.

Stainless steel appliances are hard to keep clean, agree with Michael Jacobs re sunken living room, agree with Endre Barath, Jr. with avocado, shag rugs, and tiny formal living rooms.  I find them laughable.  You see a lot of these in Denver.  Both our niece and nephew have them at the entry of their homes, as does our nephew in Minnesota.  It is a place to stick odd furniture.  A

Girl I'm so damn moody. I fall in and out of love with styles and trends-- either before or after everybody else.
In the right house a sunken living room can be cool, but I hear you on the 'what if I've had a few and need to walk across to pee in the middle of the night in total darkness ---or worse, a guest does!
I'm a throwback. I love some vintage, MCM, Art Deco, 60s and 70s groovy things in an otherwise modern home.
I love a home that flows from an inside to outside living area.
Quit compacting everything in multiple small rooms. I'd rather see two big bedrooms than four dinky tiny ones.
I do not like pot shelves, niches, or super high vaulted ceilings. They collect dust, hard to get to to change filters and clean fans, plus in my area where temperatures are extreme, it's a lot harder to cool a house that's got big ceilings.
The 80s and 90s had very few redeeming qualities. We could just skip right over that! LOL

No doubt it would be POPCORN CEILINGS

Dislike - Big, really big screen tvs. Or any screen viewable from the front door. It screams a message about the quality of people who live there.

Like - large integrated outdoor living spaces. Screened lanais and pool enclosures have made this a reality for so many Florida citizens.

Really dislike even when they were the only option....fluorescent and its ugly sister, Formica.

I no longer see a need for dens and formal dining rooms. The social graces of gathering in one place seems forgotten where television and eating once reigned.

I've only seen 2 or 3 up here and one was solved by adding a new floor to level it off. That was a long time ago and the home has been sold since then and all seems well... you cant do that with all of them 

Sunken rooms...I call them " fall down'' rooms and I think all of us have fallen in one of these homes.

The design trend that needs to go away is "popcorn" ceilings.

I assume your talking about housing but the "pants falling down" is fashion trend I wish never happened.

As far as housing goes - I'm not a fan of mid entry  homes. I don't want to come in the front door and immediately go up or down stairs. I know that it's not actually that big of a deal. I just don't like it. Millions are totally fine with it.

And yes the entire 70's thing about sunken living rooms, in the 80's conversation pits, designs with a step up here, a step or two down there. Not a fan. But I guess such features to fill a purpose. If one has had too much to drink that they can't get to the front door with out falling- they've had too much to drink to drive.

I have also taken a fall or two on unneeded steps.

that's the 60's for ya. That 'style' is making a comeback & I can hardly contain myself from puking when I see it. My friend sells that stuff to people in the city that are into MidCentury Modern.

I think we should wage all out war on mauve.

I don't care if brass is coming back - I'm sick of it.

Wood paneling should be outlawed.

I detest any rooms that are "step downs"...that's an accident waiting to happen....

On that same note... shower shalls with a big drop down. Another thing are those extremely tall exterior entry ways... hard to reach and perfect habitat for spiders, wasps and similar critters. 

Conversation pits and drop ceilings in kitchens!

You work with what you have. There are lots in the audience that like what others don't. Those sunken living room designs caught on because someone wanted them or they would not have been part of house construction. On a positive design feature note, in the early 1960's there was a construction trend in my small rural area with a pair of corner windows. To make it wrap around glass and placement of the two windows in a bedroom in the corner. It freed up options of where to park the bed instead of limiting it to pretty much one space in smaller rooms. Smart. Opened up the wall space use.  But like anything, it becomes dated as folks hanker cutting edge new and different Krista Jenkins, REALTOR® !

You have many great answers here. 

Step downs and step ups into rooms.  The only exception would be a step perhaps into a garage or a staircase to a second, or third floor or down to a basement. 

Bowties and leisure suits

The lure of the "sunken" room was all the rage and for years too! Today with a third of the United States retiring, access, function & affordability reign. Single story, lots of storage, double large garages plus yard is the preference

HGTV

Anything called a trend is an issue for me

Pop corn ceilings

I'm happy with today's trends of open floorplans (I'm finally opening up my house), white kitchens, marble looking quartz and Carrerra or Catalana quartz.

I don't get the sunken living room or the split level homes.  We've taken those out of homes my investors have remodeled.  Raised entry ways too.  Burnt out a couple jack hammers having one of those removed.

1 and 2: Black appliances (not that I miss avocado green).

Some tile and kitchen back splash designs. Time consuming to put it up. Not my taste remind me of some cheap homes that had them in the 1950s...

Wallpaper, and hear it is having a come-back - UGH!

Sunken living rooms were trendy at one time.

A friend used to have a house with a "conversation pit" in front of the fire place. I am sure it seemed like a good idea at the time.