I've posted this before but in my family we play serious Scrabble but with house rules that improve the game.
Rule 1: On your turn, but before playing your word, any letter in your hand may be swapped with any letter on the board, as long as the swap makes a valid word (some people already do this with blanks, we do it with any letter). Swap one letter at a time, as many times as you like. No points are scored for swaps, just for playing your word.
Rule 2: Dictionary may be consulted at any time to look up a specific word - however you cannot "leaf" or browse through it. Dictionary priority goes to whoever's turn it is.
The net result of this variation is that
a) the board remains MUCH more open the whole game - there are many more places to play, and the words played are more likely to be bingos or longer words, which in turn open the baord up even more. Often under official rules you get three or four letter words that just close down the future play possibilities.
b) high-point letters which usually are "luck of the draw" like Q and Z, now become skillful, since they will be reused by many players throughout the game
c) turns can take 5-10 minutes at a time :)
Source: my grandmother, who played these rules with the inventor of Scrabble back in college, before he had sold the game for mass distribution (they changed his rules to simplify them)