Started on Apple II, then a little Atari Os, Commodore (20/64/128) later w/Geos, short AmigaOS stint, then Dos later w/Windows, then OS2 with an AIX fork
AIX Fork branched to Solaris, HPUX, later HPUX dropped AIX & Solaris still moving forward with a fistful of linux distributions, Redhat, SuSE back in the day, Debian, Slackware, Ubuntu, even a little Yellowdog and a few others of others on that branch and it's still moving forward. Managed to stay away from OS/400, MVS, IRIX, Had to touch DGUX a couple times. Never got to play with NeXT. Wanted to take a look at BE a couple times but never bothered. Dear god I almost forgot SCO. I hated SCO. Never spent a lot of time with the actual BSD trunk either.
OS2 Fork primarily went back to windows after Warp and NT4 came out, that fork continues on the windows track but refuses windows 8. Server 2013 has some decent features though.
Smartphone os's, once we actually got to the point where you could choose, It's been flatline Android. Apple IOS, not to be confused with Cisco IOS (Because Apple's so original....) can stay where it is, which is away from me. Should Palm os and early variants fall under Smartphones? Or Should smartphones now fall under PDA's? Palm was decent I guess, ran it on their hardware and handspring when they were shipping.
Primarily for daily stuff, it's windows desktop to Solaris/AIX/Linux boxen that do custom work while windows servers handle support workloads (AD, things like that) and android to keep me in touch. I've got an ESX box next to my desk that's got a few different distro's on it too, but those are mostly for testing.
Reality is OS's are tools, and as much as most of you guys thrash different platforms, they've all got strengths and weaknesses. You need to pick the right tool for the right job based on capability, cost and compatibility.