Obviously, "The Best Thing" is Cynthia.
Note: I didn't say "the best thing for me", I said the "best thing". Should it be "the best person"? No. I'm merely talking about her existence on this planet. It's the best. You don't get a vote. ;)
Right now though, the best thing would be snuggling with my cat, when she puts her head on my arm and starts purring.
Or those moments when my ankle isn't killing me. Those are pretty darn good.
The Lightning winning tonight would be pretty good - because it would make people I love happy. Their happiness is the best thing.
It's interesting to think about how what is the "best thing" has changed for me over the years - those things that once seemed to be the most important thing ever and now I barely think about them.
Those little moments though - and the people you share them with. Those tend to stick around in your head. Those moments of happiness.
Oh, and Disney. That also will always be around. :)