Halo is my personal favorite. Any of the Halo games really. Great story, great characters, great gameplay. Everything is great about Halo. Except a few small things. But everything is still great really.
+1, Thumbs Up, Like, whatever, to this. ODST was my favorite for story in the series, Reach for pure fun with my idiot friends.
As to systems I have... Many. Let's see...
NES
SNES
Gamecube
Wii
Genesis (With Powerbase Converter)
CD
Saturn
Dreamcast
PSX
PS2
PS3
Xbox 360 (currently out of commission, sadly)
Gameboy
Gameboy Pocket
Gameboy Color
Gameboy Advance
Gameboy Advance SP
Nintendo DS
Nintendo 3DS
No less than 4 PCs, one custom built not only to PLAY games, but to design them
I have an extensive library of games for all of the above systems, but my favorite SERIES of games would have to be Bioshock, Final Fantasy, Halo, Mortal Kombat, Zelda, and Grandia.
I also really enjoy Red Dead Redemption, just because F*** YEAH WESTERNS!
Born 150 Years Too Late,
~Xenos, Best Bronc Stomper East of the Snake River (probably West, too)