PS3: 96
360: 29
PSP: 16
Wii: 9
DS: 4

Uncharted 2
Valyria Chronicles
Super Mario Galaxy

Heavy Rain
God of War 3
Forza Motorsport 3
Zelda TP
Mass Effect 1+2
Little Big Planet

16 disc based games + 2 in the mail and 13 Wiiware/VC titles = 31 games total

My favourites would probably be Metroid Trilogy, Mario Galaxy, and NSMBWii with honourable mentions for MK Wii and World of Goo.

Wii - 25 disc, 2 WW, 6 VC
PS3 - 8 retail, 4 Download only (2 of them free)

Favorites would be.

NSMBWii, Fire Emblem, Punch-Out!! however I think the majority of my games for both system are great.

ds: 19
dsiware: 2
wii: 25
wiiware: 5

total: 51

favorite:
1. Chrono Trigger DS
2. Zelda: TP
3. NSMBWII

22 Wii games so far, plus 9 Wiiware (and 10 Virtual Console)

Mario Kart Wii
Endless Ocean: Adventures of the Deep

errm tough to name what's in third place, Wii Sports, Mario Galaxy or Twilight Princess.

I was just thinking about this the other day, and I can't remember exact numbers, but it's something like
Wii-8
PS3-6
Xbox-50ish (I bought about 40 of them before I bought another system)
Maybe 7 DS games

Favorites (in no order)
Mass Effect 1/2 - Amazing storytelling and characters, even if the story is generic.
Demon's Souls - While it lacks a strong story, still incredibly fun, and gives a sense of accomplishment when you nail a hard boss without getting hit.
NSMBWii - Most fun I've had with a game since Halo 1 lan parties.

Call of Duty: World at War gets an honorable mention. I love me some nazi zombies, and I find the online multiplayer FAR more balanced than the MW games. Almost every gun is usable depending on play style and perk set-up.

Wii - 21

DS - 15

Hmmm.

Wii: 2 (my nephew stole my Wii a while back, I really need to get it back!)
PS3: 5
360: 20-25

My three favorites...I'll go by time played as I guess if I have played them that much, I really enjoy them: Gears 2, Modern Warfare 2 and Fallout 3.

That favorite list leaves out a TON of good games though (Uncharted, Valkyria, Lost Odyssey, Mass Effect, etc.).

2 for wii
1 for sony

I trade games all the time,so how many games I own chances all the time.