I have heard several people discuss the concept of a "very happy" bonus in Civ 5, just like you can get a "very unhappy" penalty. The main problem I see with this would be that it would still be a very useful perk for a wide empire as you could stop expansion for a while, gain a lot of happiness and then get all your cities into uber mode. An idea I had the other day changes things a bit - what if there were to be a "very happy" bonus (say, over 10/15/20 happiness, whatever is balanced) that ONLY benefits your capital, but does so greatly. For instance, it could increase all the things generated in the capital (science, culture*, gold, production etc) by a balanced percentage (say 20-30 %). This could mean that a tall empire can be more competitive as their capital can turn into an amazing city. However, expanding or conquering cities will quickly throw your happiness back down again, thus eliminating this bonus. I think this would fit the playstyle of tall quite well. A tall empire already has the bonus of more golden ages, but that is not enough to stay competitive, so why not throw in this as a bonus. A tall empire could then have at least one large city that generates a lot of everything, thus staying competitive with wide empires with specialized cities. What do you think? *considering tall is optimal for culture wins, this might cause some problems. So maybe culture should be excluded.