Can’t live without:
1Password - First install on any system I use. I only know 2 passwords by heart: my login password and my 1Password vault pw. Also supports TOTP 2 factor authentication.
Dropbox - It’s a folder, it syncs, and does this very well. Syncs my 1Password vault as well.
GrandPerspective - Visualise where your disk space is going. Every time I fire this up I find stuff I’ve forgotten about that takes up a lot of space, or something that is using disk space it shouldn’t. (Once a WiFi log hadn’t rolled over and was using 8GB of space.) - http://grandperspectiv.sourceforge.net/
Synology - It took some investment, but now I finally have a place where all my data is, safer than on one or two external drives. But that’s not all, Synology also is a fantastic home/office server with an “app store” where I can run applications, run a VPN endpoint, run Docker containers, ...
Crashplan - Not the fantastic lightweight native Mac & Linux tool I’d want, but rather a somewhat heavy Java tool. But the business model for me is great. Free replication between endpoints, ie. all my family and my NAS and unlimited replication to their datacenters for my own devices for $5/month (Crashplan Family) - http://www.crashplan.com
Plex - For me it’s always been super reliable. Server runs flawlessly on my Synology. - http://www.plex.tv
Pinboard.in - Proudly non-free, stable and boring. The author’s presentations and twitter feeds are insightful and hilarious, I’m glad to support his work.
Superduper - I use it less often than before, since I now have a proper NAS and backup solution (see above), but Superduper has helped me so much in the past it deserves a mention. Always provides a safety net when I do a migration between hdd and sdd, between systems, ... I even bought two licenses as I lost my previous one, spending another $28 on it was a no brainer. http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription...
Coda - Still my html/css/php/… editor of choice. - http://www.panic.com/coda/
Waze on my phone: best navigation I’ve ever used
youtube-dl
wget & curl - they have slightly other use cases, and I love them both. I use both of them at least weekly, mostly daily
VMware Fusion & vSphere/ESXi: still rock solid after all those years. (Disclaimer: I work there)
Other software I particularly love: Sketch (mentioned elsewhere in the thread) and Affinity Designer. I like Illustrator, but as a non-professional it’s way too expensive for me.