Among others, there is one program that is only available on a Mac that Windows cannot get anywhere close to replicating. Sure there are programs sort of like it, but none with its comprehensive capabilities.
The program is LogTen Pro. A Professional Pilot log book that is used by tens of thousands of pilots, and is considered without peer.
And again, like LogTen, there are programs for which there ARE lesser capable programs, but none that match the design, operation, and ease of the Mac versions. Examples are BoinxTV, Screenflow, Spaces (within OSX), Mars Edit2, Alfred, Little Snitch, Parallels Desktop, Prizmo, Ulysses, and others.
99% of applications can be deleted completely from a Mac by dropping its icon in the trash. No Registries.
Yosemitie (OSX 10.10.2) is extraordinary. Can't even imagine going back to Windows, and Linux can't match the GUI level that Apple has perfected. IMHO.
Cheers,
Frank