Actually noticing that the noon sun is getting progressively higher in the sky this time of year.
Calm, clear, crisp winter sun rises. Let the dog out yesterday around sunrise; it was very cold (0*F), but no wind, a bright crescent moon and sun just about to rise made it perfect.
I probably posted this already, but thunderstorms.
Watching dogs play. I will have a stupid smile on my face every. single. time.
Wrestling/playing rough with my dog.