I found this book at the library by Barbara Ann Kipfer, 14,000 Things to be Happy About. Here's the website.

Some of the content we got:

A riot of colors

Receiving gifts

Here are some of the possible content I came up with, the things that make ME happy, I am my own research/resource, thanks.

Nice weather

Clouds with silver lining/ forming a familiar shape

"Have a nice day!" with a smile

Ice cream man/Bell

Hearing your favourite song on the radio

Having the moon follow you wherever you go

A new year

Your bus arriving as you reach the bus stop

Waking up not having to go to work!

Taking pictures

Here's one more site.
100 Things to be Happy About