Let's go backwards through the Major Arcana and start with #21 - The World
Wikipedia says "The World represents an ending to a cycle of life, a pause in life before the next big cycle beginning with the fool." and while that's an accurate description, I feel there is much more to the card than just the demarcation of the end of a cycle.
The deck I typically use is The Celtic Dragon Tarot by DJ Conway and Lisa Hunt. In the card you can see the connected-ness of all things; the cycle of life from dragonett to powerful dragon to wise drake. I also appreciate that both male and female are represented. For me this card signifies that the current journey has been completed, but given the interconnectedness of all lives and paths of choice, the journey is never truly ended. However, the card in this deck seems very kind, almost bright and shiny, certainly optimistic. Were this card to come up in a reading I would most likely read it as a positive end to a chapter or situation in the person's life. I would suggest they take some moments to sit back from their emotions and look at the whole situation with the intention of acceptance.
My other oldest and most worn deck is the Crow's Magic Tarot by Londa Marks. I love this deck because it's mean, direct and to the point. I typically don't bring it out for clients unless they've walked in with attitude. This card can almost make you dizzy. You're looking down on the world a midst the timeless symbols of cycle. It makes one realize that the whole is so much bigger than a person can truly understand and it encompasses the beginning and the end of time as well as everything in between. Were this card to come up in a reading I would caution the querent to step back and look at the WHOLE picture, because their perspective may be skewed.
To be truthful, I don't believe I have had this card come up in a client's reading very often at all. I think this is because when people are requesting a reading they are typically in the middle of a situation, not at the end of the journey. More often this card comes up when I'm using the cards as a research tool for myself. I would be interested to know what other reader's experience with The World has been.