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!

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.

xfce since it came default with eos and its pretty lightweight

Plasma. I have it configured to match my workflow.

KDE customize to how ever you like to use it!

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

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.

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

@aMalayali KDE - desktop or laptop.

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

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

I haven't tried Gnome since they trashed the UI ;) and I wasn't ever much of a KDE fan so the only desktop I have ever used since the demise of Gnome 2 is XFCE.

However I've switched back to Window Maker (a window manager) on my main PC and on my VM's and I may do so on my laptops too. I don't really need a desktop so to speak, I just use wmsystray to add a system tray and things like NetworkManager, bluez etc all end up there giving me what I actually do use of a desktop.

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

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.

LXDE

I find cinnamon to strike a nice balance of speed and function if you have an ok processor, it's straight to the point and doesn't try to make you use summoning circle on your trackpad to do anything, like gnome does, but still has enough features and native configs to not make you feel like you're missing anything.

Cinnamon for me, It looks like old Windows

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.

Plasma.

Plasma KDE.
I prefer the typical Windows like layout and it offers a lot of customization options that the other DEs are missing.

I3 and KDE

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).

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.

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

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

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.

Tried many, but Xfce won for me:

• great keyboard support (tiling windows, virtual desktops, etc.)
• doesn't get in the way
• compact re UI (don't like modern GNOME look with lots of whitespace)
• lightweight

And even though I use terminals a lot (neovim, git, etc.), I never stuck with tiling window managers in the end (e.g. i3). Rather I'm heavily relying on:

• virtual desktops (8 or so)
• manual window tiling via shortcuts
• tmux

KDE on Manjaro.

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