A vanilla game of 4 player monopoly should take no more than an hour.
Catan at least has the advantage of monotonically increasing building and army points: Given enough time and even barely rational spending, a player is guaranteed to reach 10 points, no matter how alliances form and splinter.
The biggest problem we encountered in both games was the "spoiler": The player who was not in a position to win, but was in a position to determine the winner. Either you try to impose hard-to-adjudicate rules requiring "rational decisions" or you accept that a long-running game may be decided by caprice.
Obviously it only works if you play with the same people regularly, but in my experience that's actually the norm.
I'm guessing you weren't actually following the rules[1]. If you do follow the rules you'll find liquidity gets sucked out of the game by continual reselling because you are only allowed to sell unimproved properties, and have to sell houses & hotels back to the bank at half price.
[1] http://richard_wilding.tripod.com/monorules.htm#sellingprope...
Once a few monopolies did crop up, it was the remaining unimproved properties that would be swapped most often for ludicrous amounts of money to allow, say, a cash-poor player to build a few houses in the path of the current leader.
I guess you are not a fan of Diplomacy (http://en.wikipedia.org/wiki/Diplomacy_(game)), either.
Most, if not all, games of more than two players where players have some free choice eventually boil down to "you can't win it alone. You need help or a blooper from your enemy"
And that is true in sports, too. In any distance running, starting at 800m, athletes collectively make a choice whether to run a fast race or a slow race with a very fast finish. A fast sprinter will not win a fast race, so runners with lower top speed will try to make a fast race. Still, they won't want to be running in the front, they rather have another runner with lower top speed burn energy doing that.
This gets more evident the longer the distance and the larger the advantage of running in the slipstream of an opponent. Road races in cycling are perhaps the ultimate example. If "the peloton" doesn't want you to win, you have to be extremely good _and_ lucky to win.
Monopoly changed it up by making it possible to become the evil landlord, and that's what made it successful.
This is the key one.
Now, that doesn't justify turning the game into a 4 hour slog, but it may help to explain why so many people use these "wimp rules".
Also, fwiw, 99% of casual players I've seen overvalue the marquee properties like Boardwalk, etc., and undervalue the oranges, light blues, and reds.
It didn't, it was a bandage to cover the fact that Monopoly is not a very good kids game.
That rule is so rarely followed I end up in an argument with other players every time I play a game of Monopoly for attempting to play by the rules. People don't even believe that the rule exists, never mind make a conscious decision not to follow it.
The fact games of Monopoly always open with an argument is probably a big factor in me no longer playing Monopoly.
