JetBrains IDEs:
https://www.jetbrains.com/ (free alternative: Visual Studio Code plus DB tools like DBeaver, or even their community versions)
MobaXTerm: https://mobaxterm.mobatek.net/ (free alternative: mRemoteNG, PuTTY, Remmina)
GitKraken: https://gitkraken.dev/ (free alternative: SourceTree, Git Cola)
FreeFileSync: https://freefilesync.org/ (free, but I got the supporter edition because comfy software)
In those cases, the free alternatives are just worse than the paid tools.
Aside from that, mostly just VPSes (Hetzner, maybe Contabo if really on a budget) and domains (used to use NameCheap, Porkbun was kinda better, moved over to INWX cause EU option) which are good enough to run whatever FOSS I need instead of subscriptions, like Gitea and Drone CI/Woodpecker CI instead of other forges, Nextcloud instead of Dropbox, Sonatype Nexus instead of Docker Hub, Uptime Kuma and Zabbix and Matomo and Skywalking/GlitchTip instead of similar observability solutions, Grav instead of managed Wordpress for blogging, Kanboard/OpenProject instead of cloud Jira, RustDesk instead of RealVNC and so on. E-mail is a mixed bag: the free cloud ones are good enough for personal usage and self-hosted Docker mail server is better for no rate limits, e.g. alerts from my monitoring to my own address.
Recently, some of the AI cloud subscriptions because getting my own GPUs in my homelab is beyond my means (maybe once Intel Arc Pro B60 are available): primarily Google's Gemini model or Claude's Sonnet although lower cost options would also be quite nice, maybe ERNIE-4.5 or Qwen3-Coder or whatever. I actually used to pay for GitHub Copilot but am also looking in the direction of just using the APIs of the various providers (or OpenRouter) directly to avoid fixes fees and have more lenient rate limits.