For my personal use, I generally run some flavor of Debian Linux. The specifics can vary wildly, as I’m comfortable with everything from a bare-bones Tiling Window Manager like AWM, to a heavyweight like KDE Plasma. My desktop is currently running Elementary OS with some usability tweaks, my laptop is running Linux Mint, and my netbook is running xUbuntu.
On the server side, I also tend towards Debian, but primarily because it’s (currently) possible to use a non-systemd init system. I like having the freedom to pick and chose what runs on my servers, and having the Linux kernel support no-reboot upgrades seems silly if the init system doesn’t support it.
When I use an IDE, I’m very partial to Netbeans. It has plugins for all the languages I (currently) write, and has some really fantastic refactoring and project management tools built in. Netbeans is not lightweight, so I also use gedit pretty extensively. With the gedit-plugins package, I can add autocomplete, bracket matching, and automatic whitespace functionality, making it function as quite the nice little editor.
I run an Intel i7-2600k set in an Asus P8Z68-V Pro motherboard and 8gb of RAM. I’ve got three monitors in an Obutto oZone ergonomic desk, and for flight or space sims I’ve got a Saitek Rhino x55 HOTAS.