As happy, quick, etc. as anything
Definition 1 of 1
Pro Tip 1/3Informal Use
This phrase expresses strong emotions in a relaxed, informal way, often found in casual conversations. 
She was as happy as anything when she found her lost puppy!
Pro Tip 2/3Expressive Emphasis
Adds emphasis to an adjective to heighten its meaning without being literal. 
After winning the game, he felt as brave as anything.
Pro Tip 3/3Exaggeration
The phrase tends to exaggerate for effect but not to be taken as an exact measure. 
The cat ran as quick as anything when it saw the dog.