We played: Istanbul, which i actually enjoyed. Mind you, it was my first game of this - having read on BGG that after you play it a few times, it becomes easier to plan a good route across the action spaces on the board. Our game of this took about 2 hours, and was pretty close - apart from the winner (who obviously had 5 rubies at the end) 3 of the other 4 of us had reached 4 rubies, and I was poised to get my 5th on my next turn.
We played a total of 4 games of the quick-fire card game The Resistance (we didn't have the expansion though). The first game of this took 15 minutes, the second took 20 minutes, the third took 15 minutes again, and the last took 10 minutes. 5 is the minimum number of players. This is a really fun deduction/bluffing game, although our experience is that it's nearly impossible for the resistance to win. In fact in each of our games of this, the spies won. But trying to figure out who's a spy and who isn't, with all the arguing and accusations that occur, is fun. Could make a good game to play drunk, too, as long as you and the other players don't get violent...
We tried a game of Mysterium, that took just over an hour. I think the version we played was the 2015 one. The one of us whose game it was, who had actually played it before, took on the role of the helpful ghost. Now, i really like the idea of this game, and the way the ghost gives clues to the players - the game is vaguely similar to Cluedo - the ghost is of someone who's been murdered, and each of the other players will have a corresponding deck of 3 cards, consisting of the murderer, the location of the murder, and finally the method. These are drawn by the ghost and so the ghost has to give each player clues so they can guess each part of the deck - the murderer first, then the location, and finally the method. the ghost does this by assigning each player clue cards, again drawn at random but then the ghost can decide who to give each card to (and can give more than 1 to a player). The problem we found is that the number of turns you get is just too little. I think at the end only 1 of us had managed to guess all 3 of their murder cards.
Finally, we played Terra Mystica. One of the guys had picked this up at the Boardgames Expo in Birmingham. It took us 2 hours 50 minutes. I enjoyed it, but it is quite a detailed game, and there are many options as far as what to aim to build, and how to score victory points. I certainly think it warrants some further play. It doesn't really have a conflict mechanism (although it is possible for one player to "steal" another player's terrain hex if the first player terraforms it but doesn't build on it straight away). I like the way the terrforming mechanism works so it's not easy for a player to steam ahead and grab lots of land
Istanbul @ Amazon
The Resistance @ Amazon
Mysterium @ Amazon
Terra Mystica @ Amazon