What game is so easy it is impossible to lose and even the stongest boss is puny?  Most battles are as one sided as Bambi meets Godzilla.

I am going to say Okami.  I never lost a signle life and most bosses can be defeated within minutes.  I killed the final boss in about 10-30 minutes and took almost no damage.

Final Fantasy 8... or Persona 3 FES.

Probably Dora Saves the Snow Princess..

You can't die and out of the 100 or so collectables you only actually need something like 5 to pass the level.

Avatar.

I't depends on the player's skill really. Me personally, I love a challenge! I always start any game on the hardest mode possible.
On-Topic, MGS4 was probably the easiest game I ever played. I got the "BiggBoss Emblem" after four days of the games release.

Daxter (PSP)

Kingdom Hearts II-still love the game

You Have To Burn The Rope

WWF Royal Rumble on the SNES.

ice age for the gba, just press on forward and you win.