Let's get this community popping with some useful information. Reddit's sysadmin subreddit seemed like a place of complainers, I look forward to having actual productive conversation in this community.
Kinda new to the whole sysadmin thing, but tmux has been an absolute game changer for me. No more remote desktop for long running processes, I can just do everything from ssh.
One of the first installs on any new computer. Can’t live without it once you have it! It makes it so quick and easy to grab a screenshot, draw some arrows/boxes/whatever, then just copy and paste.
Big fan of the IODD. I love having a ton of bootable images ready to go on a single drive. I mostly use it to boot disk wiping software, disk imaging software, and malware removal tools but it also serves as my main flash drive with common software and scripts I use a lot.
Vscode. Yes it's managed by Microsoft, and yes it's a newage emacs (it can do anything with add-ons), but regardless of what your tasks are it's probably going to be useful.
My company has been moving onto Kubernetes recently and I've found Lens to be very helpful with it. It has a nice cluster dashboard and has inbuilt shortcuts to jump onto containers, see logs, etc.
For systems creation, provisioning and config management Hashicorp's terraform and packer, and RedHat's ansible are indispensable.
govc for managing guests in vCenter.
jq for parsing json.
I like tmux better than screen, but use both.
Not really a tool, per se, but Netbox is a great DCIM/IPAM application for managing your infrastructure.
Just learned about it and am currently learning, but Apache JMeter looks like a useful tool for running automated load testing against different kinds of services.
I have a bunch of pages and tasks that can be run from the right click menu in Inventory so not only myself, but also less technical team members can run them.
It also is nice to RDP or VNC into a machine with a keyboard shortcut.
remote desktop manager by devolutions
powershell - duh
ansible
vscode
sharex or greenshot (I've been favoring sharex lately)
firefox with the container plugin (so I can keep the authentication contexts separate for all the o365 consoles I have to deal with)
KeepassXC. Covers all I need for my personal password management, I like putting my encrypted databases to e.g. OneDrive instead of relying to something solely cloud-based.
Vivaldi Browser. Because I like messing around with tabs and this is one is supporting side tabs (instead having them on top), you can have Chrome extensions as well.
I've been in the weird space of on-prem "cloud" infrastructure (mostly kubernetes) for the last seven years but I've been doing infra, middleware, and devops for more than twenty years and have my own way of working that's nearly GUI-free.
Lots of onprem cluster work. I generally use k3s with an nfs provisioner. I've gotten into using ansible with AWX. Summerwind gh runners. I still stick with vim but having read comments, see I need to check out tmux over ssh. I like uptime kuma for basic monitors and while I setup signoz I still go back to just using Datadog.