These bits of Ms Office : Excel, Powerpoint, Outlook,Project Pro (not part of Office pro suite but available as a separate product). Things like Word are easily replicated elsewhere although as I have office I use Word too.
Other MS stuff -- only file explorer -- but it really needs an overhaul. It's looking very dated now.
Non MS stuff : Hedisql (for SQL queries from remote DB's), SAPGUI (SAP front end for connecting to Work SAP HANA systems), and HYPER-V to be able to test Windows and other OS'es from a physical Windows machine. Photoshop and Lightroom (Classic --pre subscription) too are programs I have to run on Windows.
DBpoweramp for music manager / cd ripper etc. (VLC and GIMP are good but I run those from Linux anyway).
And of course any sensible browser -- I use FF as it handle's pdf's easily enough without needing additional software for reading etc.
Apart from Hyper-V I run this stuff usually as a VM from a Linux laptop / workstation -- I'm not a gamer so VM performance is for me more than adequate on decent machines.
I've oodles of storage and run Windows from vhdx files usually a windows partition for me is around 44 GB with quite a bit spare so I don't need things like Macrium any more. For data backup I just rsync from a Linux NAS, and every so often just copy the vhdx file(s) to the NAS for system backup. OK uses more storage but if you've got around 30TB online --Who cares. With Linux software RAID 0 (Mdadm) you can combine all sorts of different capacity HDD's into a single or multiple arrays -- backup storage doesn't have to be mega fast if you run backup jobs say at night etc, and saves chucking a load of decently functioning older spinners into landfill.
Remember though even on a NAS you need to also back up critical stuff -- cloud and external devices are good for this too. BTW with the stand alone version of GPARTED I can do if necessary a bare metal restore of the NAS OS in about 7 mins flat -- fine for my purposes -- and this NAS runs 24/7 and has been for months now without any reboots etc needed. This NAS won't run W11 -- BIOS MBR machine for starters - but it certainly can run a slew of Windows 11 VM's as the machine has 128GB RAM and multi physical processors plus 2 separate GPU's.
Cheers
jimbo