Games, Rulesets, Genres, and Collections

Does every other DM out there stick to one system, one world, or one genre?

In my youth as a DM/GM I ran a LOT of different games (heavy on the D&D of course) -

Dungeons & Dragons - White Box Edition
Basic Dungeons & Dragons (Basic thru to Immortals Rules & Rules Cyclopedia)
Advanced Dungeons & Dragons 1st Edition
Advanced Dungeons & Dragons 2nd Edition
Dungeons & Dragons - Third Edition
Dungeons & Dragons 3.5
Castles & Crusades (which counts as D&D for me at least)
Dungeons & Dragons 4th Edition
Hackmaster (up to 4th, I don't really rate the new Hackmaster Basic)

Call of Cthulhu (I stopped running it around 5th Edition, though I do have the excellent D20 rules)
Chill (Pacesetter)
Dark Conspiracy (AWESOME Fluff, OK system)

Star Trek (Fasa)
Star Trek (LUG)
Star Trek (Decipher)

Traveller
Traveller 2300
Twilight 2000

Mythus - Dangerous Journeys
Lejendary Adventures

Metascape - Guild Space

Mechwarrior - The Battletech RPG

Shadowrun (1st thru 3rd Edition, not keen of 4th Edition)

Marvel Super Heroes
DC Super Heroes
Silver Age Sentinels (my personal favourite Supers game)
Golden Heroes (a FANTASTIC Supers Game IMHO - despite its flaws)

Star Wars (West End Games - still one of the BEST RPG's ever written)
Star Wars D20 (NOT the Saga edition, I really don't rate it at all)

I own a lot of RPG's besides - but the above are the ones I have actually run games for. But these days, I don't know why the "song" of Fantasy RPG's is calling me more and more.

I don't know whether its my inherrant romantic nature, or my Love of all things fantastical (in part thanks to my Mum) - but its there.

My RPG Book Shelves looks like a D&D Library, but (not unusual for me - as I like to write my own) very few Scenarios. I find bought Scenarios very "constricting" - they aren't written with your players (or their characters and any relevant backstories) in mind.

I wonder if any other "Veteran" DM/GM's feel the same, are they narrowing their focus - or is it the other way around, are they spreading their wings?

The "Realm" of Dungeons and Dragons has always been "Home" to me, and I imagine it always will . . . .