I haven't played many games of Scrabble, but you wanted my take on things, so here it is. I find Scrabble challenging, I don't find too many flaws with the game, but I don't like it. I think that there's two problems with word games in general - one, the biggest vocabulary always wins, and two, there's virtually no luck, or all luck based on the tiles. Now, don't get me wrong, Scrabble is a good game. The board is interesting in terms of the various tiles, but it boils down to who knows the most before the game. To me, that's not much of a game when all players don't have a reasonably equal chance to win.
Boggle is a step in the right direction, since it removes the luck of tile draws, thus giving every player equal access to words, but the main problem still remains. The person who knows the most words will once again win.
I do find challenge in word games when it's timed to see how many I can get in a given period. The problem is that these are best suited for computer games, little social networking apps, and phone games, thus they are best as single player games. Even then, the experience is less than satisfying. Maybe it has to do with pure skill games and the way that players can get better than everyone else through practice or certain other means. If one person is always going to win the game, or almost alway win, what's the point in playing?
So the question becomes how do you improve Scrabble. Well, the first idea is make sure you play with people right around your vocabulary level. Sure, sometimes you'll know more words, sometimes others will, but that makes the game closer. Now, this isn't perfect since there's not a great way to quantify vocabulary knowledge. So what might help? How about a list of possible words, something like 30-50 words so players can play quickly even if they get stuck. I really don't have great solutions here.
Some other word games that might scratch the Scrabble itch, but do it in a more compact or fun way.
Word on the Street (Junior version as well)
It's a two player/team game where one team reads a category and the other side has to come up with a word that fits the category. They then spell the word moving each letter in the word one spot closer to their side. This causes people to come up with words using b's d's, g's, w's, etc. and stretches players vocabulary. It will favor the bigger vocabulary, but there are ways to win before that becomes an issue. It may not be the best alternative, but it's out there.
I don't know of any other word games, but I know they exist. If they don't, maybe it's a sign that the masses have given up their thesauruses in favor of simplistic language and that word games just aren't all that fun to play with the same group over and over again.