Almost all modern video games offer some way to save your progress through them. Some offer multiple ways by including checkpoint systems, autosaves, etc. Most games also have a pause menu which can be used as a sort of mid-play save. A fundamental problem in many games is that of the user forgetting what he was doing when he saved the game.
Not very many save systems that I know of take action against the all-too-common occurance of saving your game and then picking it back up hours, days, months, or years later and having no idea how to proceed. The key to this problem in my mind is to allow the player himself or the game system to provide context for the current game state that either jogs the players memory or informs him directly of most of what he needs to know.
There are multiple solutions to this problem, not all of which involve the save system. Having a clear and detailed objective system is helpful and could possibly be the solution in and of itself. I advocate using both a save preview system as well as the ability for players to write notes to themselves and attach them to saves.
A save preview system already exists in many games, whether it shows you the time spent on the save, the level or subarea in which the player saved, a screenshot taken at the time of save, a custom name, or whatever. These are all context clues that both help the player determine which save in the menu is the one he wants to load as well as provide him with information about the game state of that save.
User interface designers seem most often to have the first function in mind rather than the second. I think the expansion of the save preview to include all the relevant information is an important step. Whether the save preview is accessed by mousing over a selected save, selecting a save, or pushing a button on a selected save, it should take up as much screen space as it needs to display its information.
My idea of attaching text notes to save games is inspired by a player-made mod for Morrowind which allows the player to write in the journal whatever they want. The journal already handily records the players objectives and activities, but the addition of free writing capabilities allows for more detailed, nuanced, and personal use of the journal.
The automatic recording system used in many games can capture all sorts of details and data but often it does a poor job sorting or otherwise presenting it to the player in a way that is meaningful. If the quest objective is one line (as it often is) but the player is in the middle of the quest and currently preoccupied by solving a complex puzzle when he’s interrupted, there is no way for the system to know what approach he was taking to solving the puzzle.
Even with a fine-tuned player tracking system (which is also useful for dynamic difficulty systems and many other things) there is no accounting for the psychological element. In turn-based strategy games, for example, the players current or future strategies are all in his head (and extremely important).
A few sentences such as “Building nukes in preparation for strike against the French. Need to expand westward for more resources.” Can provide enough context for the player to get back into things after even a lengthy break. And this system certainly saves the player the tedious task of surveying the entire game state in detail.