A few Royal Flushes, all online, with a Jack-high str8 flush my highest hand live.
I used to treat myself to a glass of champagne whenever I got any kind of str8 flush, but with the online boom, I had to throw that policy out the window to avoid becoming a raging alcoholic

. Nowadays if I get a
Royal Flush, I make a note to treat myself to a glass of French Champagne (forget that crap in California

).
Your question asked for the "best hand" and that can be the hand that won you the most money as well. My highest tournament win was $16,000 in April 2007, and the hand that got me that was (wait for it ...) As Td, which earned me the key pot near the end of heads up play. It earned me $16,000 so it wins the "Best Hand" nod from me

.