Linux

GNOME

I'm a KDE guy and use it myself on my notebook, but GNOME with its multitouch gestures and polished (if a little inflexible) workflow is also an excellent fit.

i3 and never looked back!

XFCE minimal but good looking. You could also go for MATE or Cinnamon..

xfce since it came default with eos and its pretty lightweight

GNOME, despite the critiques it receives it's the most polished one and the one that gives me less problems

If you haven't tried them, I recommend giving them a try. They all have something to offer.

I don't use Gnome, for example. People knock on it a bit BUT a large group of people swear by it for workflow.

KDE Plasma is the dream for anyone who likes to tweak settings. I used it on my laptop for a long time and it is very convenient. It also manages power and monitor settings very well. In terms of memory usage it is now similar to XFCE.

XFCE is perfect for people who don't like change. It is a slow moving DE; tried and true.

Right now I am using LXQt. Not sure why I decided to do that. It looks ok. It is fast and light. That's it's claim to fame. It can be used with different WMs which is nice.

Are there any particular DE’s you like on a laptop, because of things like power consumption and efficiency that would not come normally into consideration for a desktop?

I can't say I've ever looked into it. But, I found that KDE handled things very well. I used my laptop for full workdays, getting 11 hours out of it.

i3
the less I need a mouse on a laptop, the better

edit: ok, you specifically asked for a full fledged DE and not just a WM. well, I picked what I needed and with Manjaro i3 as base, I had a nice place to start

Tiling window managers like i3 are imho nice for laptops, since they do not waste any space and can be easily controllen via keyboard. Takes a while to get used to them, however.

I3 and KDE

I like Enlightenment. It uses 400 MB of RAM on my old laptop/

sway, the i3 clone for Wayland. I'm really happy with it, even on my Intel iGPU + Nvidia GPU laptop.

Cinnamon for me, It looks like old Windows

KDE customize to how ever you like to use it!

Of the ones I tried, my top 3 would be cinnamon, budgie, and kde. KDE is probably the best bet for modern features ATM, cinnamon for simplicity.

@aMalayali KDE - desktop or laptop.

I use kde on my laptop

I'm the type of person who gets tired of a DE after using it for too long, so I'm using Budgie right now and I really like it. However XFCE is pretty nice, too, it's what I used to use.

I recently switched to xfce.
I used KDE exclusively since 2004. That's a very long time but KDE Plasma in combination with nvidia got worse, what felt like, every single day over the last years, so it finally came to the point where I had no choice to look for something that works better.
Super happy with xfce after I set it up almost exactly like my KDE setup. Sure there are some thing that are not as "well rounded" than some of the excellent Plasma features but over all it works great!

I recently switched from i3 to hyprland and quite like it. Wayland still has some issues, but the better scaling makes it worth it.

Started out with xfce, used lxde for a short while... it was too minimalistic for my taste. Tried KDE for about a week, that was the oposite, too flashy. Went back to xfce, haven't tried anything else since. It's a sweet spot IMO.

I'm the weirdo over in the corner using TDE (Trinity Desktop Environment, forked from KDE3) on both my desktop and laptop.

DE: KDE & Cinnamon. WM: Awesome & I3

On laptops Gnome has a big advantage in the multitouch gestures for the touchpad, and as everyone says it's pretty polished. But lately I've been using KDE since it offers a lot more functionality and customization out of the box. Most of it's apps are like a swiss army knife and I love that. KDE is also catching up in the multitouch gesture department.

XFCE is my favourite on both desktop and laptop. It's light weight, has all the features I need and feels really snappy, especially when all animations are turned off (which I always do).

If I want to use a graphical user interface, I generally use KDE Plasma.

Gnome hands down has the best laptop experience. If you follow the intended workflow of using tiled windows and many workspaces. You can get to a very large number of windows, without getting lost, even with just the laptop screen.

Additionally the paradigm does translate well to a desktop for the times you are docked.

I'm using xfce everywhere, it's simply the most lightweight and I got so used to fast reactivity that I couldn't care less about barebone icons (and even those have come a long way since).

xfce. Lightweight, stays out of my way, and doesn’t eat up much screen real estate.

I love Sway and been using it for a year or so. Never looked back

KDE

If there was a modern Window Maker, I would use that. I mean with a notification area and when I minimize Firefox or Chrome I don't get five icons in the corner and it works as a Wayland compositor and supports HiDPI scaling.

I recommen GNOME, but I usually use Hyprland.

On my laptops I like the same one as on my desktops: KDE Plasma. With any other I quickly start missing the features that KDE Plasma offers and the configurability and customizability. And It is also quite lightweight for all that it offers. Others often offer much less and consume more resources then KDE Plasma.

I'm really liking Budgie, can't wait for version 11 when they ditch the gnome libs/apps.

@aMalayali I'm quite happy with Cinnamon in the moment but I know what you mean. If my daily work experience with Cinnamon would suffer, I would also go back to XFCE.