Agree with Rob, the kinds of songs he lists have definitely become generation transiting acoustic anthems - just take a look at YouTube and you'll see examples of hundreds of young musicians playing such songs. The key difference today being that such songs have become a part of contemporary DIY music making traditions via the means of recorded sound, the internet and also importantly via 'Greatest Rock Songs for Guitar' chord books, rather than the exclusively oral tradition of yore - though that plays it's part also.