Though I’m not sure it’s still in print, and despite it being a long game (typically, it take us most of a night, but you mentionned Civilization that is quite long too), I’m going to mention my favorite boardgame ever : Roma.
The theme is the roman republic. Each player is leading a roman faction and victory is achived by seizing power (being elected consul for life, attack Rome when coming back with your victorious armies, there are several ways…). It’s mostly a diplomatic game (since there’s an elaborate senate phase when you vote to elect officials, choose generals, send senators to take care of some remote province so he won’t bother you for some time, vote populist laws, assassinate your concurrents, agree to vote for a player as Censor in exchange for some denarii and providing he doesn’t prosecute you for you stealing in the treasury when you were propretor, etc…), but with a great deal of variety in your possibilities of action.
The most interesting part of the game is the fact that if Rome collapses, all players lose. So, you’re playing at the same time against the game and against the other players. You’re always walking on a fine line, because you have to cooperate if you don’t want Rome to collapse (and there are plenty of ways it can : bankruptcy, unrest and revolt of the plebs, military victory of Rome’s ennemies…), but you must keep your own interest in mind.
It’s quite often a dilemna : for instance should you vote to send an excellent general belonging to another player with a mighty army to fight the Carthaginians? If you don’t Rome might fall and you could lose. If you do, he could become hugely popular or alternatively march on Rome after his victory, and you could lose. An option could be to assassinate him after, but which other player is going to take the risk of assassinating a popular victorious general?
This is this part that made it the best game I know (at least the best long game).
I play various board game of widely different kind quite often but since a number of them are french or german games (for some reason, Germany produces excellent boardgames), I don’t know whether they are publisghed in the USA and under what name.
However, a game creator I know has an “ideal game library” on his site, with a detailled and bilingual description of his (long) list of “must have” games (his owns an incredible number of games), with the american, french german versions mentionned. Here’s the link .
I notice looking on the first page “Adel Verpflichtet”, another game I like a lot, quick to play and fun (essentially a bluff/double guessing game). And also “Britannia” , another favorite of mine in the “long” category (you play, in turn, the various people, from the celts to William the conqueror, who invaded Great Britain and try to accumulate as much point as possible by seizing and keeping territory as long as you can). A number of games already mentionned in this thread (like the settlers of Catane, indeed a great game) are presented on his site, and even some “old classics” (like “Clue”). The list is in alphabetic order of the french title, so if you’re searching for a specific title it can be disorienting.
Though I don’t necessarily like all his favorite games (he tends not to like much very long games/comlicated rules), I think he did a great job presenting them, that’s why I mention his site.
