I thought the first Oasis album was called Definitely Maybe, and I couldn't tell you about the Libertines (apart from the fact that the singer has serious problems).
But as to Neil Young, his best acoustic stuff is either Harvest (most accessible) or After The Goldrush (my personal favourite). Rust Never Sleeps has an accoustic half and a stunning electric second part, I'd also give a mention to Freedom, a mid 80s classic when most of his contemporaries were churning out rubbish, and On The Beach, Zuma and Tonight's The Night (his so-called doom trilogy) but they are pretty heavy going.