I haven't played a lot of games (especially on console), but it seems that most console games still adopt a checkpoint based saving system (with some like Final Fantasy allowing you to save anywhere in the overworld).  Most PC games don't seem to use this checkpoint system - you can save anywhere, though the game may automatically save when you reach a checkpoint.

Personally this has been a turn off for me for a number of games, as I really don't know how much time I can dedicate when I do begin to play something.
What do you think of checkpoint based saving?  Do you think this improves the game by enforcing certain restrictions?  Or why do you think it's still used?