I've mentioned before that I prefer Mercurial to Git, at least for my own work. That said, git has a nice feature that allows you to cherry pick revisions to merge between branches. That's extremely useful if you want to move a single change between branches and not do a full branch merge. Turns out mercurial has that ability, too, but it goes by a slightly different name.
I still use the mutt email client when I'm remoted into some of my FreeBSD servers. It might not be the most eye pleasing email client ever, but it's powerful, lightweight and fast.
What do you do if you don't have dos2unix, need to convert a file or three from DOS (or Mac) format to UNIX format, but all you have is Emacs? Well, of course you use Emacs for the file conversion, what else?
I used XEmacs quite a lot in the 2000s before I switched back to the more stable GNU Emacs. That was back then before GNU Emacs offered a stable official Windows build when XEmacs did, and at the time I was doing a lot of Windows development.
I've been an unashamed fan of the old "cheese grater" Mac Pro due to its sturdiness and expandability. Yes, they're not the most elegant bit of kit out there but they are well built. And most importantly for me, they are expandable by plugging things inside the case, not by creating a Gordian Knot of hubs, Thunderbolt cables, USB cables and stacks of external disks all evenly scattered around a trash can. Oh, and they're designed to go under a desk. Where mine happens to live, right next to my dual boot Linux/Windows development box.