What are some light-hearted happy games you enjoy?

Trinity Universe (PS3)
Nintendogs (DS)
Super Mario 3D Land (3DS)

Lets see, what games can Dr. ShinZero prescribe for you...

SNES
-Donkey Kong Country
-Kirby Super Star
-Super Punch Out

Wii
-Paper Mario Series
-Animal Crossing Series
-House of the Dead: Overkill (It's too hilarious to be considered gritty)
-Sonic Colors
-Punch Out
-De Blob
-Mario Strikers Charged
-Metal Slug Anthology
-Tatsunoko vs. Capcom

PS3
-Jak and Daxter: The Precursor Legacy
-SSX 2012
-Split/Second Velocity
-Burnout Paradise
-Saints Row: The Third (The sheer lack of fucks given to logic makes this more lighthearted than 2)
-The Sly Cooper Collection
-Dynasty Warriors: Gundam 3 (If you ignore the plot)
-X-Blades, due to how bad of a game it is.

not much I can add other then wario ware (ds/wii)

Peggle is a happy game

Most of the ones I like or played have already been listed.

Although I was really into Recettear - An Item Shops Tale for a while.