What is the best airplane seat for a cross-country flight?

I'm 6ft tall, and I'm flying from New York to California. Can anyone recommend the best seat on the plane? I don't have any budget constraints.<br><br>&#x200B;<br><br>edit: I'm looking for the best seat, not necessarily first-class.<br><br>&#x200B;<br><br>edit 2: I should have been more specific. 6'1'', slender build, no bottom or back problems, I prefer to be in a window seat, I'm a smoker but won't smoke on the plane, and I have budget constraints but I don't mind splurging on an airline ticket. I do mind the price since I'm not made of money. I don't like direct flights because they're boring (I'm a weirdo).<br><br>&#x200B;<br><br>edit 3: Thank you all for your recommendations so far! I am going to make a round trip, so I will be flying on two flights. I'll be flying from New York to California on Flight A, and then from California to New York on Flight B. Flight A will depart early in the morning, while Flight B will depart in the late afternoon. Flight B will be a direct flight.<br><br>&#x200B;<br><br>edit 4: Okay so I booked seats 16C on Flight A and 18D on Flight B.