D&D, Dungeon World, Fate, X-Crawl, Fantasy Trip.

I'll play damn near anything, at least once.  What I'll buy, or ref, is a different issue.

Dark Dungeons
ACKS
D&D 5E (playtest)
Fate Accelerated Edition
World of Darkness (new)
Star Wars - Edge of the Empire
Black Crusade
Dark Heresy
Rogue Trader
Swords & Wizardry White Box

Most of those were fairly brief one-shots or PbP games that didn't get very far before dying off.

Spread out over 4 groups:

Earthdawn
Shadowrun 5
Dungeon Crawl Classics
BRP/Magic World
Pathfinder
Lamentations of the Flame Princess
Swords & Wizardry

Most of the time was spent with Earthdawn, Pathfinder and Magic World.

In the last couple of years we've played
Icons
Bounty Hunters of the Atomic Wastelands
Star Wars D6
Fate Accelerated
Rocket Age
Feng Shui
Ghostbusters
Dr Who

There may have been a few more, not sure.

In the last two years (and in no particular order):

Amber (could be heavily house ruled for all I know)
Basic D&D (RC with house rules)
Maelstrom (1541)
Apocalypse World
Dungeon World (con game)
Mouse Guard (con game)
Advanced Fighting Fantasy 2e
Vampire the Redemption
Conspiracy X (1e)
All Flesh Must Be Eaten
Overkill (home brew)
Battlestar Galactica (con game with Cold City engine)
3:16 (con game, run by the author)

Dungeon World, SLA, Ars Magica, Leverage, Yggdrasil, Star Wars D6, Marvel Super Heroes, Floating Vagabond, Laundry, WFRP, Dark Heresy, Feng Shui, Night's Black Agents... probably forgot a few.

Pathfinder, because it's run by the one online text game place I actually like and because none of my friends live nearby (and I live out in the boonies).

Our campaigns usually last somewhere from six months to a year, so each of my groups will only have played three or four games in any given two year period. As it happens, both groups have each played four games in the last two years. All our playing is face-to-face.

With my main group of fortysomethings (playing about every other week)...

Mage: The Ascension (first edition core book only - I've had the game since the week it came out and this is the first time we've actually played it after over 20 years).

Deadlands (again first edition core book only - this campaign ground to a halt due to intra-party strife that ended up with a gunfight and lots of dynamite exploding; but everyone was cool with that).

Blood, Guts & Glory (that's my d20/Rolemaster 2e mash-up set in post-apocalypse Elizabethan England).

Eldritch Skies (John Snead's Lovecraftian sci-fi game - which to me is Lovecraft done right; we started off with the Unisystem version but while we loved the setting we didn't get on with the mechanics so half-way through the campaign we switched to the new Savage Worlds version which we're liking a lot more).

My secondary group, mostly comprised of the teen and pre-teen children of the primary group, have played (playing most weeks)...

D&D 4e (the adults were fine with this, but the kids didn't like it much so we stopped quite quickly).

D&D 3e (with my "3.Y" house rules which cut out the min-maxing and  bring it closer to AD&D; the kids thought it was too complicated - they're used to Dark Dungeons - but they happily played to the end of the campaign).

Masks (my mash-up of ICONS and FASERIP Marvel; everyone liked the system, but the kids weren't really that into the superhero genre, so the campaign didn't last very long).

5e Playtest (we're still playing this - we'll switch to the PHB when it comes out - and thoroughly enjoying it; everyone prefers it to both 3e and 4e).

Hmm, five, I think: Stars Without Number, ICONS, Call of Cthulhu, DnD 5e, and Gamma World.

Pathfinder
Stars Without Number
DCC RPG
Lamentations of the Flame Princess
WEG Starwars 1E

Fantasy Craft
Savage Worlds
Supers!
Hero System 6E
Fate Core
Marvel Heroic Roleplay
Wild Talents

Call of Cthulhu
Star Frontiers
Mongoose Traveller

And I've been a player in a number of Gurps 4e campaigns.

Two or three, depending on how you want to count it. Dresden Files RPG, I've tried to run a couple of things in Fate Core, and Fight!.

Oh, and I already voted, but I realized that within the last two years, I've also played a (very) little D&D, and tried Amber. Once.

GMed:
4e Essentials
7th Sea

Played:
Star Wars SAGA
Stars Without Number (ongoing PBP on this forum)

Harn
Legend (Mongoose)
Dragon Warriors
Stars without Number
Other Dust
Scarlett Warriors