I've you're still playing Sony's Gran Turismo 5 or the Resistance series, then you might want to get your kicks while they last. Sony will be pulling the plug on the servers, effectively killing off the online portions of these games. March 28th will see the end of Resistance, and May 20th is the day for Gran Turismo 5.
Thus is the way of gaming's future while we move into an age where servers dictate everything. Your favorite games, the one's you've had great memories playing online with your friends are no more than a business decision away from being shut down forever. Permanence is nothing, your memories couldn't be less important.
Gran Turismo 5 is somewhat understandable since Gran Turismo 6 has been released. The series evolves in such a way that it renders the older games obsolete, unless of course, you have hundreds of hours sunk into Gran Turismo 5 and unlocked all the cars. It's understandable that you might not be especially keen to take part in Gran Turismo 6's microtransaction system, so this is Sony's way of taking away that choice.
Resistance is a less acceptable decision, especially Resistance 2 and its online co-op mode. I've never played it myself, but I remember it got a lot of praise for its unique take on class base character customization, essentially laying the foundation for games like Borderlands and every other co-op shooter since. It might be something worth taking a look at years down the road, but alas, you're never going to be able to again. Sorry.
I'm old and was raised during a day and age when physical games can be revisited whenever I want. The most I've suffered in this online crackdown is Phantasy Star Online, which still has plenty of fan severs running if I ever decide to get back into it. I don't have many impressionable moments from the last few years, and I hold no sentimentality towards online modes.
Some younger people or even hardcore online fans just might though, and they'll never be able to revisit classic favorites like I can. This would be like Konami taking away your multiplayer options for Contra on the NES, something that just would not fly. As gaming gets older, there needs to be a stronger sense of preservation so we don't have lost pieces of history the way film does.
Good luck in seeing your favorite games surviving the next twenty five years.