I'm a bit of a gamer. There are a few computer games I play a great deal of, and I enjoy board games and tabletop roleplaying. There are two common features in most of the games I play: Long and complex.
I like Battletech. It's a tactical game you play on maps or terrain and either one of hundreds of "official" units, or, just as often, ones that you''ve designed yourself. Simulating five minutes of combat with twelve-meter tall futuristic war machines can take five hours - and I've very cheerfully enjoyed playing Battletech for five hours.
Lately, Twilight Imperium has become one of my favorite games. It's like a more complex and less violent version of Risk, and similar to a nice long Battletech game, it lasts long enough that you can schedule a pizza break in the middle.
I've run and played tabletop RPGs - roleplaying games, mostly different kinds of Dungeons and Dragons - and a good session length is about four hours. The "whole" game ideally lasts for semesters, possibly years, of sessions every week or two, and the fellow running the game gets to decide which optional rulebooks to use. Talk about complexity - there's literally over a thousand pages of "core" material for many RPGs, and the optional rules can fill bookshelves.
Defense of the Ancients is probably my favorite computer game. It's a particular custom map on Warcraft III - and where a normal WCIII game involves several types of units and a choice between a dozen or so heroes with a few items, DotA is a ten-player romp with somewhere around a hundred different heroes with similar numbers of items. Some of which work together, some of which don't, and others of which transform into new items when combined with others. A full game will usually last an hour.
The drawback is that when you play long games, you pretty much have to schedule them, and you don't always have the time to get in a game. The drawback of complex games is that it can get difficult to find people to play them with.